salutation in greeting, c. 1200, from Old Norse heill "health, prosperity, good luck," or a similar Scandinavian source, and in part from Old English shortening of wæs hæil "be healthy" (see health; and compare wassail).
The interj. hail is thus an abbreviated sentence expressing a wish, 'be whole,' i. e., be in good health, and equiv. to L. salve, plural salvete, or ave, plural avete .... [Century Dictionary]
"in good health, robust," Old English hal "healthy, sound, safe; entire; uninjured; genuine, straightforward," from Proto-Germanic *hailaz(source also of Old Frisian hel"complete, full; firm" (of ground), Old High German heil, Old Norse heill "hale, sound," Gothic hails "hale"), from PIE *kailo- "whole, uninjured, of good omen" (see health). The Scottish and northern English form of whole and with a more etymological spelling. It later acquired a literary sense of "free from infirmity" (1734), especially in reference to the aged. Related: Haleness.
A similar formation appears in Old English wes þu hal, but this is not recorded as a drinking salutation. Sense extended c. 1300 to "liquor in which healths were drunk," especially spiced ale used in Christmas Eve celebrations. Meaning "a carousal, reveling" first attested c. 1600. Wassailing "custom of going caroling house to house at Christmas time" is recorded from 1742.
The spelling with wh- developed early 15c. The sense in whole number is from early 14c. Whole milk is from 1782. On the whole "considering all facts or circumstances" is from 1690s. For phrase whole hog, see hog (n.).
1660s, "state of being unmarried, voluntary abstention from marriage," formed in English, with abstract noun suffix -cy + Latin caelibatus "state of being unmarried," from caelebs "unmarried," a word of uncertain origin. Perhaps from PIE *kaiwelo- "alone" + lib(h)s- "living." De Vaan suggests as an alternative PIE *kehi-lo- "whole," which would relate it to health (q.v.): "[I]f this developed to 'unboundness, celibacy', it may explain the meaning 'unmarried' of caelebs-."
Originally and through the 19c. celibacy was opposed to marriage, and celibacy, except as a religious vow, often was frowned upon as leading to (or being an excuse for) sexual indulgence and debauchery among bachelors. By 1950s it was being used sometimes in a sense of "voluntary abstinence from sexuality," without reference to marriage.
Old English halig "holy, consecrated, sacred; godly; ecclesiastical," from Proto-Germanic *hailaga- (source also of Old Norse heilagr, Danish hellig, Old Frisian helich "holy," Old Saxon helag, Middle Dutch helich, Old High German heilag, German heilig, Gothic hailags "holy"), from PIE *kailo- "whole, uninjured" (see health). Adopted at conversion for Latin sanctus.
The primary (pre-Christian) meaning is not possible to determine, but probably it was "that must be preserved whole or intact, that cannot be transgressed or violated," and connected with Old English hal (see health) and Old High German heil "health, happiness, good luck" (source of the German salutation Heil). Holy water was in Old English.
Holy is stronger and more absolute than any word of cognate meaning. That which is sacred may derive its sanction from man ; that which is holy has its sanctity directly from God or as connected with him. Hence we speak of the Holy Bible, and the sacred writings of the Hindus. He who is holy is absolutely or essentially free from sin; sacred is not a word of personal character. The opposite of holy is sinful or wicked; that of sacred is secular, profane, or common. [Century Dictionary, 1895]
Holy has been used as an intensifying word from 1837; in expletives since 1880s (such as holy smoke, 1883, holy mackerel, 1876, holy cow, 1914, holy moly etc.), most of them euphemisms for holy Christ or holy Moses. Holy Ghost was in Old English (in Middle English often written as one word). Holy League is used of various European alliances; the Holy Alliance was that formed personally by the sovereigns of Russia, Austria, and Prussia in 1815; it ended in 1830.
mid-13c., faith, feith, fei, fai "faithfulness to a trust or promise; loyalty to a person; honesty, truthfulness," from Anglo-French and Old French feid, foi "faith, belief, trust, confidence; pledge" (11c.), from Latin fides "trust, faith, confidence, reliance, credence, belief," from root of fidere "to trust,"from PIE root *bheidh- "to trust, confide, persuade." For sense evolution, see belief. Accommodated to other English abstract nouns in -th (truth, health, etc.).
From early 14c. as "assent of the mind to the truth of a statement for which there is incomplete evidence," especially "belief in religious matters" (matched with hope and charity). Since mid-14c. in reference to the Christian church or religion; from late 14c. in reference to any religious persuasion.
And faith is neither the submission of the reason, nor is it the acceptance, simply and absolutely upon testimony, of what reason cannot reach. Faith is: the being able to cleave to a power of goodness appealing to our higher and real self, not to our lower and apparent self. [Matthew Arnold, "Literature & Dogma," 1873]
From late 14c. as "confidence in a person or thing with reference to truthfulness or reliability," also "fidelity of one spouse to another." Also in Middle English "a sworn oath," hence its frequent use in Middle English oaths and asseverations (par ma fay, mid-13c.; bi my fay, c. 1300).
early 15c., sanite, "healthy condition, health," a sense now obsolete, from Old French sanité "health," from Latin sanitatem (nominative sanitas) "health, soundness of body; sanity, soundness of mind; reason; correctness of speech;" from sanus "healthy; sane" (see sane). Meaning "soundness of mind" is attested from c. 1600.
"favorable to health, wholesome," 1540s, from Latin salubris "promoting health, healthful," from salus (genitive salutis) "welfare, health" (from PIE root *sol- "whole, well-kept"). Originally of foods, medicine; in reference to air, climate, etc., by 1610s. Related: Salubriously; salubriousness.
"recovering strength and health after sickness," 1650s, from French convalescent, from Latin convalescentem (nominative convalescens), present participle of convalescere "thrive, regain health, begin to grow strong or well," from assimilated form of com-, here perhaps an intensive prefix (see com-), + valescere "to begin to grow strong," inchoative of valere "to be strong" (from PIE root *wal- "to be strong").
As a noun, "one who is recovering strength and health after sickness or debility," attested from 1758.