"ruse, deception," 1937, from earlier adjectival meaning "assumed, feigned" (1620s), a figurative extension of the verbal phrase on the notion of putting on costumes or disguises. To put on (v.), of clothes, garments, etc., is by early 15c.; see from put (v.) + on (adv.). Hence "clothe, cover, assume as covering" (mid-15c.) and "assume the garb or appearance of" (real or feigned), 1520s. The expression put (someone) on "play a trick on, deceive" (by 1958) seems to be a back-formation from the noun.