SOUR
—adjective. 1 acid in taste or smell, esp. Because unripe or fermented. 2 morose; bitter. 3 (of a thing) unpleasant; distasteful. 4 (of the soil) dank. —verb. Make or become sour. ? go (or turn) sour 1 turn out badly. 2 lose one`s keenness. ? sourly adverb. Sourness none. [old english]