noun A drink made by mixing an alcoholic beverage with lemon juice or lime juice. (a rum sour)
verb Make or become sour. (water soured with tamarind)
adjective Having an acid taste like lemon or vinegar. (she sampled the wine and found it was sour) Feeling or expressing resentment, disappointment, or anger. (she was quite a different woman from the sour, bored creature I had known) (of soil) deficient in lime and usually dank. (Our soil is on the sour side and lays wet in spots, as the old-timers say.) (of petroleum or natural gas) containing a relatively high sulfur content.