英语词源字典 - 在线词源网站

retract (v.)[retract 词源字典]: early 15c., "to draw (something) back," from Old French retracter (14c.) and directly from Latin retractus, past participle of retrahere "to draw back" (see retraction). Sense of "to revoke, recant, take back" is attested from 1540s, probably a back-formation from retraction. Related: Retracted; retracting.[retract etymology, retract origin, 英语词源]
retractile: "Capable of being retracted", Late 18th century: from retract, on the pattern of contractile.
retractability: "Ability (of a component part) to be retracted", Mid 19th cent.; earliest use found in The Penny Magazine. From retractable + -ity: see -bility.