1590s, "an undoing, ruin," from defeat (v.). From c. 1600 as "act of overcoming in a military contest;" by 1690s of other contests and struggles.
late 14c., defeten, diffaiten, "overcome (with sorrow or anger)," from Anglo-French defeter, from Old French desfait, past participle of desfaire "to undo," from Vulgar Latin *diffacere "undo, destroy," from Latin dis- "un-, not" (see dis-) + facere "to do, perform," from PIE root *dhe- "to set, put."
From early 15c. as "bring ruination, cause destruction" (now obsolete in this sense); from late 15c. as "frustrate, prevent the success of." Sense of "deprive of something expected, desired or striven for" is from 1530s. Meaning "overcome in a contest of any kind" is from 1560s. Related: Defeated; defeating. Compare defect, deficient.
"conduct tending to bring about acceptance of (the certainty of) defeat" [OED], 1918; see defeatist.
"drive (a body of troops) into disordered flight by defeat," c. 1600, from rout (n.). Hence "defeat or repulse thoroughly." Related: Routed; routing.
"to checkmate," c. 1300, from Old French mater "to checkmate, defeat, overcome," from mat "checkmated" (see checkmate (v.)).
mid-14c., "defeat in battle, overthrow," from Old French desconfiture "rout, defeat" (12c.; Modern French déconfiture), from desconfire (see discomfit). Sense of "frustration, disappointment" is from late 14c. Confused since 15c. with discomforture "discouragement, distress."