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).
Phrases and idioms:
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.
Derivatives:
sourish adj. sourly adv. sourness n.
Etymology: OE sur f. Gmc