Online Etymology Dictionary

healthy (adj.): 1550s, from health + -y (2). Slightly earlier in the same sense was healthsome (1530s). Related: Healthiness.
It is wrong to say that certain articles of food are healthy or unhealthy. Wholesome and unwholesome are the right words. A pig may be healthy or unhealthy while alive; but after he is killed and becomes pork, he can enjoy no health, and suffer no sickness. [Eliza Leslie, "Miss Leslie's Behaviour Book," Philadelphia, 1839]
heap (n.): Old English heap "pile, great number, multitude" (of things or persons), from West Germanic *haupaz (cf. Old Saxon hop, Old Frisian hap, Middle Low German hupe, Dutch hoop, German Haufe "heap"), perhaps related to Old English heah "high." Slang meaning "old car" is attested from 1924. As a characteristic word in American Indian English speech, "a lot, a great deal," by 1832.
heap (v.): Old English heapian "collect, heap up, bring together;" from heap (n.). Related: Heaped; heaping. Cf. Old High German houfon "to heap."
hear (v.): Old English heran (Anglian), (ge)hieran, hyran (West Saxon) "to hear, listen (to), obey, follow; accede to, grant; judge," from Proto-Germanic *hausjan (cf. Old Norse heyra, Old Frisian hora, Dutch horen, German hören, Gothic hausjan), perhaps from PIE *kous- "to hear" (see acoustic).

For spelling, see see head (n.); spelling distinction between hear and here developed 1200-1550. Old English also had the excellent adjective hiersum "ready to hear, obedient," literally "hear-some" with suffix from handsome, etc. Hear, hear! (1680s) was originally imperative, used as an exclamation to call attention to a speaker's words; now a general cheer of approval. Originally it was hear him!
heard: past tense and past participle of hear, Old English herde.
hearer (n.): mid-14c., agent noun from hear.
hearing (n.): "perception by ear," early 13c., from present participle of hear. Meaning "a listening to evidence in a court of law" is from 1570s.
hearken (v.): Old English heorcnian, a suffixed form of *heorcian, root of hark; from Proto-Germanic *hausjan (see hear). Harken is the usual spelling in U.S. and probably is better justified by etymology; hearken likely is from influence of hear.
hearkening (n.): Old English heorcnunge "harkening, listening, power of hearing" (see hearken).
hearsay (n.): 1530s, perhaps mid-15c., from phrase to hear say.
hearse (n.): c.1300 (late 13c. in Anglo-Latin), "flat framework for candles, hung over a coffin," from Old French herce "long rake, harrow," from Medieval Latin hercia, from Latin hirpicem (nominative hirpex) "harrow," from Oscan hirpus "wolf," supposedly in allusion to its teeth. Or the Oscan word may be related to Latin hirsutus "shaggy, bristly." The funeral display so called because it resembled a harrow, a large rake for breaking up soil. For spelling, see head. Sense extended to other temporary frameworks built over dead people, then to "vehicle for carrying a body," a sense first recorded 1640s.
heart (n.): Old English heorte "heart; breast, soul, spirit, will, desire; courage; mind, intellect," from Proto-Germanic *khertan- (cf. Old Saxon herta, Old Frisian herte, Old Norse hjarta, Dutch hart, Old High German herza, German Herz, Gothic hairto), from PIE *kerd- "heart" (cf. Greek kardia, Latin cor, Old Irish cride, Welsh craidd, Hittite kir, Lithuanian širdis, Russian serdce "heart," Breton kreiz "middle," Old Church Slavonic sreda "middle").

Spelling with -ea- is c.1500, reflecting what then was a long vowel, and remained when pronunciation shifted. Most of the figurative senses were present in Old English, including "intellect, memory," now only in by heart. Heart attack attested from 1935; heart disease is from 1864. The card game hearts is so called from 1886.
heart-rending (adj.): also heartrending, heart rending, 1680s, from heart + present participle of rend. Related: Heart-rendingly.
heart-throb (n.): also heartthrob, 1839, from heart (n.) + throb (n.). Of persons who inspire romantic feelings, from 1928.
heartache (n.): Old English heortece, in the sense of a physical pain; c.1600 in sense of "anguish of mind;" from heart + ache. Old English did, however, have heartsarnes "grief," literally "heart-soreness."
heartbeat (n.): 1850, from heart + beat (n.). From the beginning used as a figure for "a very brief time."
heartbreak (n.): 1580s, from heart + break (n.). Related: Heartbreaking.
heartbreaker (n.): 1660s, originally "a fetching lock of hair;" of persons, from 1863; agent noun from heartbreak.
heartbroken (adj.): 1580s, present participle of heartbreak.
heartburn (n.): mid-13c., herte-brine "lust," later "heartburn, indigestion" (mid-15c.); also herte-brenning "anger, bitterness" (c.1400), also "heartburn" (mid-15c.). See heart + burn (n.). Also cf. cardiac.
hearted (adj.): now used only in combinations, meaning "at heart," since c.1200, first attested in hard-hearted; see heart. Related: heartedly.
hearten (v.): c.1200, "to encourage," from heart + -en (1). A verb formed from figurative sense of heart. Related: Heartened; heartening.
heartfelt (adj.): also heart-felt, 1734, from heart + past tense of feel (v.).
heartful (adj.): "devout, earnest," mid-14c., from heart + -ful. Related: Heartfully.
hearth (n.): Old English heorð "hearth, fire," in transferred use "house, home," from West Germanic *hertho "burning place" (cf. Old Saxon and Old Frisian herth, Middle Dutch hert, Dutch haard, German Herd "floor, ground, fireplace"), from PIE *kerta-, from root *ker- "heat, fire" (see carbon).
heartily (adv.): c.1300, from hearty + -ly (2).
heartland (n.): 1904, first recorded in geo-political writings of English geographer H.J. MacKinder (1861-1947), from heart in figurative sense "center, core" + land (n.).
heartless (adj.): Old English heortleas "dispirited, dejected;" see heart + -less. In Middle English with expanded senses "lacking in courage; foolish; listless; half-hearted; sluggish." Sense of "callous, cruel" is not certainly attested before Shelley used it in 1816. Literal meaning "lacking a heart, lifeless" (mid-15c.) is rare. Related: Heartlessly; heartlessness.
heartsick (adj.): "despondent," late 14c., from heart + sick. Old English heortseoc meant "ill from heart disease."
heartstrings (n.): late 15c., originally literal, in old anatomy theory "the tendons and nerves that brace the heart;" from heart + string (n.). Transferred and figurative sense from 1590s.
heartwarming (adj.): 1899, from heart + present participle of warm (v.).
hearty (adj.): late 14c., "courageous; spirited, zealous;" also "loyal, faithful; sagacious, wise," from heart + -y (2). Related: Heartiness.
heat (n.): Old English hætu, hæto "heat, warmth; fervor ardor," from Proto-Germanic *haiti- "heat" (cf. Old Saxon hittia, Old Norse hiti, Old Frisian hete, German hitze "heat," Gothic heito "fever"), from PIE *kaid-, from root *kai- "heat." The same root is the source of Old English hat "hot" and hæða "hot weather" (see hot).

Meaning "a single course in a race," especially a horse race, is from 1660s, perhaps from earlier figurative sense of "violent action; a single intense effort" (late 14c.), or meaning "run given to a horse to prepare for a race" (1570s). This later expanded to "division of a race or contest when there are too many contestants to run at once," the winners of each heat then competing in a final race. Meaning "sexual excitement in animals" is from 1768. Meaning "trouble with the police" attested by 1920. Heat wave "period of excessive hot weather" first attested 1890; earlier in reference to solar cycles.
heat (v.): Old English hætan "to heat; to become hot," from Proto-Germanic *haitijanam (see heat (n.)). Related: Heated (with many variants in Middle English); heating. Cf. Middle Dutch heeten, Dutch heten, German heizen "to heat."
heated (adj.): in figurative sense "agitated, inflamed," 1590s, past participle adjective from heat (v.). Related: Heatedly.
heater (n.): c.1500, of persons, agent noun from heat. Of devices, from 1660s. Baseball slang meaning "fastball" is attested by 1985.
heath (n.): Old English hæð "untilled land, tract of wasteland," earlier "heather," influenced by Old Norse heiðr "field," from Proto-Germanic *haithiz (cf. Old Saxon hetha, Old High German heida "heather," Dutch heide "heath," Gothic haiþi "field"), from PIE *kaito "forest, uncultivated land" (cf. Old Irish ciad, Welsh coed, Breton coet "wood, forest").
heathen (n.): Old English hæðen "not Christian or Jewish," also as a noun, "heathen man" (especially of the Danes), merged with Old Norse heiðinn (adj.) "heathen, pagan."

Perhaps literally "pertaining to one inhabiting uncultivated land," from heath + -en (2). But historically assumed to be from Gothic haiþno "gentile, heathen woman," used by Ulfilas in the first translation of the Bible into a Germanic language (cf. Mark vii:26, for "Greek"); if so it could be a derivative of Gothic haiþi "dwelling on the heath," but this sense is not recorded. It may have been chosen on model of Latin paganus, with its root sense of "rural" (see pagan), or for resemblance to Greek ethne (see gentile), or it may be a literal borrowing of that Greek word, perhaps via Armenian hethanos [Sophus Bugge]. Like other basic words for exclusively Christian ideas (e.g. church) it likely would have come first into Gothic and then spread to other Germanic languages.
heathenish (adj.): Old English hæðenisc; see heathen + -ish.
heathenism (n.): c.1600, from heathen + -ism. An Old English word for it was hæðennes, and a later one was heathenry (1560s).
heather (n.): early 14c., hathir, from Old English *hæddre, Scottish or northern England dialect name for Calluna vulgaris, probably altered by heath, but real connection to that word is unlikely [Liberman, OED]. Perhaps originally Celtic. As a fem. proper name little used in U.S. before 1935, but a top-15 name for girls born there 1971-1989.
heave (v.): Old English hebban "to lift, raise; lift up, exalt" (class VI strong verb; past tense hof, past participle hafen), from Proto-Germanic *hafjan (cf. Old Norse hefja, Dutch heffen, German heben, Gothic hafjan "to lift, raise"), from PIE *kap-yo-, from root *kap- "to grasp" (see capable).

Related to Old English habban "to hold, possess." Intransitive use by c.1200. Meaning "to throw" is from 1590s. Sense of "retch, make an effort to vomit" is first attested c.1600. Related: Heaved; heaving. Nautical heave-ho was a chant in lifting (c.1300, hevelow).
heave (n.): 1570s, from heave (v.).
heaven (n.): Old English heofon "home of God," earlier "sky, firmament," probably from Proto-Germanic *hibin-, dissimilated from *himin- (cf. Low German heben, Old Norse himinn, Gothic himins, Old Frisian himul, Dutch hemel, German Himmel "heaven, sky"), perhaps from PIE root *kem-/*kam- "to cover" (cf. chemise). [Watkins derives it elaborately from PIE *ak- "sharp" via *akman- "stone, sharp stone," then "stony vault of heaven"].

Plural use in sense of "sky" is probably from Ptolemaic theory of space composed of many spheres, but it also formerly was used in the same sense as the singular in Biblical language, as a translation of Hebrew plural shamayim. Heaven-sent (adj.) attested from 1640s.
heavenly (adj.): Old English heofonlic "celestial; chaste;" see heaven + -ly (1). Meaning "beautiful, divinely lovely" is late 14c., often (though not originally) with reference to the celestial "music of the spheres;" weakened sense of "excellent, enjoyable" is first recorded 1874. The heavenly bodies (stars, planets, etc.) attested from late 14c. Related: Heavenliness.
heavens (n.): "realm of the heavenly bodies," 1670s, from heaven.
heavily (adv.): Old English hefiglice "violently, intensely; sorrowfully; sluggishly," from hefig (see heavy) + -ly (2).
heaviness (n.): Old English hefigness "heaviness, weight; burden, affliction; dullness, torpor;" see heavy + -ness.
heavy (adj.): Old English hefig "heavy, having much weight; important, grave; oppressive; slow, dull," from Proto-Germanic *hafiga "containing something; having weight" (cf. Old Saxon, Old High German hebig, Old Norse hofugr, Middle Dutch hevich, Dutch hevig), from PIE *kap- "to grasp" (see capable). Jazz slang sense of "profound, serious" is from 1937 but would have been comprehensible to an Anglo-Saxon. Heavy industry recorded from 1932. Heavy metal attested by 1839 in chemistry; in nautical jargon from at least 1744 in sense "large-caliber guns on a ship.
While we undervalue the nicely-balanced weight of broadsides which have lately been brought forward with all the grave precision of Cocker, we are well aware of the decided advantages of heavy metal. ["United Services Journal," London, 1830]
As a type of rock music, from 1972.
heavy (n.): mid-13c., "something heavy; heaviness," from heavy (adj.). Theatrical sense of "villain" is 1880.