sitO.E. sittan "to be seated, to seat oneself" (class V strong verb; past tense sæt, pp. seten), from P.Gmc. *setjanan (cf. O.S. sittian, O.N. sitja, O.Fris. sitta, M.Du. sitten, Du. zitten, O.H.G. sizzan, Ger. sitzen, Goth. sitan), from PIE base *sed- "to sit" (see
sedentary). In ref. to a legislative assembly, from 1518. Meaning "to baby-sit" is recorded from 1966. Sitting room first recorded 1771. Slang sitting duck "easy target" first recorded 1944; lit. sense is from 1867 (it is considered not sporting to shoot at one). Sitting pretty is from 1921. To sit on one's hands was originally "to withhold applause" (1926); later, "to do nothing" (1959). To sit around "be idle, do nothing" is 1915, Amer.Eng. To sit out "not take part" is from 1626.