WordNet sense 1 (the taste experience when vinegar or lemon juice is taken into the mouth):

sourness, tartness

WordNet sense 2 (the property of being acidic):

acidity

WordNet sense 3 (pleasing to the sense of taste):

tasty

WordNet sense 4 (in an unpalatable state):

off, turned

WordNet sense 5 (having turned bad):

soured

WordNet sense 6 (tasting sour like a lemon):

tart

WordNet sense 7 (being sour to the taste):

acid

WordNet sense 8 (tasting or smelling like vinegar):

vinegary, acetous, acetose, vinegarish

WordNet sense 9 (make sour or more sour):

acidify, acetify, acidulate

WordNet sense 10 (showing a brooding ill humor):

dark, dour, glowering, glum, moody, morose, saturnine, sullen

WordNet sense 11 (having an irritable and unpleasant disposition):

ill-natured

WordNet sense 12 (smelling of fermentation or staleness):

rancid

WordNet sense 13 (having an unpleasant smell):

malodorous, stinky, malodourous, ill-smelling, unpeasant-smelling

WordNet sense 14 (inaccurate in pitch):

off-key, false

WordNet sense 15 (not in harmony):

inharmonious, unharmonious

WordNet sense 16 (go sour or spoil):

ferment, turn, work, ferment