Etymology
Advertisement
ease (v.)
c. 1300, "to help, assist," from Old French aiser, from aise (see ease (n.)). Meaning "to give ease, mitigate, alleviate, relieve from pain or care" is from mid-14c. Meaning "render less difficult" is from 1630s; the sense of "to relax one's efforts" is from 1863 (with up by 1907, earlier with a more specific sense in sailing). Farmer reports ease in a slang sense of "to content a woman" sexually, with an 1861 date. Related: Eased; easing.
Related entries & more 
Advertisement
ease (n.)

c. 1200, "physical comfort, undisturbed state of the body; tranquility, peace of mind," from Old French aise "comfort, pleasure, well-being; opportunity," which is of uncertain origin. According to Watkins is ultimately from Latin adiacens "lying at," present participle of adiacere "lie at, border upon, lie near," from ad "to" (see ad-) + iacere "to lie, rest," literally "to throw" (from PIE root *ye- "to throw, impel"). Recent dictionaries in English and French seem to support this derivation, though older sources found objections to it. Compare adagio.

At ease "at rest, at peace, in comfort" is from late 14c.; as a military order (1802) the word denotes "freedom from stiffness or formality."

Related entries & more 
easeful (adj.)

"attended by or affording ease; promoting rest or comfort; quiet, peaceful, restful," late 14c., from ease (n.) + -ful.

Related entries & more 
easement (n.)
late 14c., "compensation, redress," from Old French aisement "comfort, convenience; use, enjoyment," from aisier "to ease," from aise (see ease (n.)). The meaning "legal right or privilege of using something not one's own" is from early 15c.
Related entries & more 
disease (n.)

early 14c., "discomfort, inconvenience, distress, trouble," from Old French desaise "lack, want; discomfort, distress; trouble, misfortune; disease, sickness," from des- "without, away" (see dis-) + aise "ease" (see ease (n.)). Restricted pathological sense of "sickness, illness" in English emerged by late 14c.; the word still sometimes was used in its literal sense early 17c., and was somewhat revived 20c., usually with a hyphen (dis-ease).

Related entries & more 
Advertisement
malaise (n.)

c. 1300, maleise "pain, suffering; sorrow, anxiety," also, by late 14c., "disease, sickness," from Old French malaise "difficulty, suffering, hardship," literally "ill-ease," from mal "bad" (see mal-) + aise "ease" (see ease (n.)). The current use, in the sense of "unease, discomfort," especially "an indefinite feeling of uneasiness," is perhaps a mid-18c. reborrowing from Modern French. A Middle English verbal form, malasen "to trouble, distress" (mid-15c.), from Old French malaisier, did not endure.

Related entries & more 
easy (adj.)

c. 1200, "at ease, having ease, free from bodily discomfort and anxiety," from Old French aisie "comfortable, at ease, rich, well-off" (Modern French aisé), past participle of aisier "to put at ease," from aise (see ease (n.)). Sense of "not difficult, requiring no great labor or effort" is from late 13c.; of conditions, "offering comfort, pleasant," early 14c. Of persons, "lenient, kind, calm, gentle," late 14c. Meaning "readily yielding, not difficult of persuasion" is from 1610s. The concept of "not difficult" was expressed in Old English and early Middle English by eaþe (adv.), ieþe (adj.), apparently common West Germanic (compare German öde "empty, desolate," but of disputed origin.

Easy Street is from 1890. Easy money attested by 1889; to take it easy "relax" is from 1804 (be easy in same sense recorded from 1746); easy does it recorded by 1835. Easy rider (1912) was African-American vernacular for "sexually satisfying lover." The easy listening radio format is from 1961, defined by William Safire (in 1986) as, "the music of the 60's played in the 80's with the style of the 40's." Related: Easier; easiest.

Related entries & more 
*ye- 

*yē-, Proto-Indo-European root meaning "to throw, impel."

It forms all or part of: abject; abjection; adjacence; adjacent; adjective; aphetic; catheter; circumjacent; conjecture; deject; ease; ejaculate; eject; enema; gist; ictus; interjacent; inject; interject; interjection; jess; jet (v.1) "to sprout or spurt forth, shoot out;" jet (n.1) "stream of water;" jete; jetsam; jettison; jetton; jetty (n.) "pier;" joist; jut; object; objection; objective; paresis; project; projectile; reject; rejection; subjacent; subject; subjective; trajectory.

It is the hypothetical source of/evidence for its existence is provided by: Hittite ijami "I make;" Latin iacere "to throw, cast."

Related entries & more 
facility (n.)

early 15c., "gentleness, lightness," from Old French facilité "easiness, ease," from Latin facilitatem (nominative facilitas) "easiness, ease, fluency, willingness," from facilis "easy to do," from facere "to do" (from PIE root *dhe- "to set, put"). First in a medical book:

If it be nede forto smyte [the head] wiþ a malle, be it done with esynez or facilite [transl. Guy de Chauliac's "Grande Chirurgie"]

Its sense in English expanded to "opportunity" (1510s), to "aptitude, ease, quality of being easily done" (1530s). Meaning "place for doing something" which makes the word so beloved of journalists and fuzzy writers, first recorded 1872, via notion of "physical means by which (something) can be easily done."

Related entries & more 
conveniences (n.)

"material appliances or arrangements conducive to personal comfort," 1670s, plural of convenience in the sense "that which gives ease or comfort; a convenient article or appliance."

Related entries & more