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knockout (n.): also knock-out, in fighting, 1887, from verbal phrase knock out "to stun by a blow for a 10-count" in boxing, short for to knock out of time; see knock (v.) + out. Slang meaning "attractive person" is from 1892. To knock oneself out "make a great effort" is from 1936.
technical (adj.): 1610s, "skilled in a particular art or subject," formed in English from technic + -al (1), or in part from Greek tekhnikos "of art; systematic," in reference to persons "skillful, artistic," from tekhne "art, skill, craft" (see techno-).

The sense narrowed to "having to do with the mechanical arts" (1727). Basketball technical foul (one which does not involve contact between opponents) is recorded from 1934. Boxing technical knock-out (one in which the loser is not knocked out) is recorded from 1921; abbreviation TKO is from 1940s. Technical difficulty is from 1805.