adj., n., & v.
adj. 1 having an acid taste like lemon or vinegar, esp. because of unripeness (sour apples). 2 a (of food, esp. milk or bread) bad because of fermentation. b smelling or tasting rancid or unpleasant. 3 (of a person, temper, etc.) harsh; morose; bitter. 4 (of a thing) unpleasant; distasteful. 5 (of the soil) deficient in lime and usually dank.
n. 1 US a drink with lemon- or lime-juice (whisky sour). 2 an acid solution used in bleaching etc.
v.tr. & intr. make or become sour (soured the cream; soured by misfortune). go (or turn) sour 1 (of food etc.) become sour. 2 turn out badly (the job went sour on him). 3 lose one's keenness. sour cream cream deliberately fermented by adding bacteria. sour grapes resentful disparagement of something one cannot personally acquire. sour mash US a brewing- or distilling-mash made acid to promote fermentation. sourish adj. sourly adv. sourness n.
[ OE sur f. Gmc ]