anesthetic adj.

Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).

In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.

1721, "loss of feeling," medical Latin, from Greek anaisthēsia "want of feeling or perception, lack of sensation (to pleasure or pain)," abstract noun from an- "without" (see an- (1)) + aisthēsis "feeling" (from PIE root *au- "to perceive"). For the abstract noun ending, see -ia.

As "a procedure for the prevention of pain in surgical operations," attested from 1846. Aesthesia "capacity for feeling" is attested in English from 1853, perhaps a back-formation.

alternative spelling of anesthetic (q.v.). See æ (1).