Origin and history of feign

c. 1300, "enfeebled; wearied, exhausted," from Old French faint, feint "false, deceitful; sham, artificial; weak, faint, lazy, indolent, cowardly," past participle of feindre "hesitate, falter, be indolent, show weakness, avoid one's duty by pretending," from Latin fingere "to touch, handle; devise; fabricate, alter, change" (from PIE root *dheigh- "to form, build"). Also from c. 1300 as "deceitful; unreliable; false." Meaning "wanting in spirit or courage, cowardly" (a sense now mostly encountered in faint-hearted) is from early 14c. From early 15c. of actions, functions, colors, etc., "weak, feeble, poor." Meaning "producing a feeble impression upon the senses" is from 1650s.

1670s, "a false show, assumed appearance;" 1680s as "a pretended blow, movement made to deceive an opponent as to the object of an attack," from French feinte "a feint, sham, fabrication, pretense," abstract noun from Old French feint "false, deceitful; sham, artificial; weak, faint, lazy, indolent" (13c.), originally fem. past participle of feindre "pretend, shirk," from Latin fingere "to touch, handle; devise; fabricate, alter, change" (from PIE root *dheigh- "to form, build").

Borrowed c. 1300 as adjective ("deceitful," also "enfeebled; lacking in courage;" see feint (v.)), but long obsolete in that sense except as a trade spelling of faint among stationers and paper-makers. Also as a noun in Middle English with senses "false-heartedness" (early 14c.), "bodily weakness" (c. 1400).