c. 1200, worn-down form of Old English alswa "quite so, wholly so," literally "all so" (see also), fully established by c. 1400. Equivalent to so; any distinction in use is purely idiomatic. Related to German als "as, than," from Middle High German also.
Phrase as well "just as much" is recorded from late 15c.; the phrase also can imply "as well as not," "as well as anything else." Phrase as if, in Kantian metaphysics (translating German als ob), introducing a supposition not to be taken literally, is from 1892; as an interjection of incredulity (as if!; i.e. "as if that really could happen") is attested from 1995. It duplicates Latin quasi. Phrase as it were "as if it were so" is attested from late 14c.
ancient southern constellation, 1590s, from Latin āra "altar, hearth," from PIE root *as- "to burn, glow."
type of flowering shrub, 1753, Modern Latin, coined by Linnaeus from the fem. of Greek azaleos "dry," related to azein "to dry up," probably from PIE root *as- "to burn, glow." The plant thrives in sandy soil.
"powdery remains of fire," Old English æsce "ash," from Proto-Germanic *askon (source also of Old Norse and Swedish aska, Old High German asca, German asche, Middle Dutch asche, Gothic azgo "ashes"), from PIE root *as- "to burn, glow." Spanish and Portuguese ascua "red-hot coal" are Germanic loan-words.
An ancient symbol of grief or repentance; hence Ash Wednesday (c. 1300), from custom introduced by Pope Gregory the Great of sprinkling ashes on the heads of penitents on the first day of Lent. Ashes meaning "mortal remains of a person" is late 13c., in reference to the ancient custom of cremation. Meaning "Finely pulverized lava thrown from a volcano" is from 1660s.
1650s, "dry, parched, without moisture," from French aride "dry" (15c.) or directly from Latin aridus "dry, arid, parched," from arere "to be dry," from PIE root *as- "to burn, glow." Figurative sense of "uninteresting" is from 1827. Related: Aridly; aridness.
"heat of passion or desire," mid-15c., from Old French ardure "heat, glow; inflammation; passion" (12c., Modern French ardeur), from Latin ardorem (nominative ardor) "a flame, fire, burning, heat;" also of feelings, etc., "eagerness, zeal," from ardere "to burn," from PIE root *as- "to burn, glow." In Middle English used of base passions; since Milton's time of noble ones.
1520s, "sideways, asquint, out of the corner of the eye," of obscure origin. OED has separate listings for askance and obsolete Middle English askance(s) and no indication of a connection, but Barnhart and others derive the newer word from the older one. The Middle English word, recorded early 14c. as ase quances and found later in Chaucer, meant "in such a way that; even as; as if;" and as an adverb "insincerely, deceptively." It has been analyzed as a compound of as and Old French quanses (pronounced "kanses") "how if," from Latin quam "how" + si "if."
The E[nglish] as is, accordingly, redundant, and merely added by way of partial explanation. The M.E. askances means "as if" in other passages, but here means, "as if it were," i.e. "possibly," "perhaps"; as said above. Sometimes the final s is dropped .... [Walter W. Skeat, glossary to Chaucer's "Man of Law's Tale," 1894]
Also see discussion in Leo Spitzer, "Anglo-French Etymologies," Philological Quarterly 24.23 (1945), and see OED entry for askance (adv.) for discussion of the mysterious ask- word cluster in English. Other guesses about the origin of askance include Old French a escone, from past participle of a word for "hidden;" Italian a scancio "obliquely, slantingly;" or that it is a cognate of askew.