| piquant(adjective, strong, sharp, powerful, hot) |
| acidulate(verb, upset, poison, alienate, disillusion) |
| ferment(verb, action, dull, turn, provoke) |
| hostile(adjective, mean, hard, severe, evil) |
| nasty(adjective, mean, bad, hard, severe) |
| not good |
| off-key(adjective, hard, right, severe, sharp) |
| spoil(verb, action, dull, turn, decay) |
| unripe(adjective, state, bitter, acid, tart) |
| vinegary(adjective, sharp, difficult, harsh, bitter) |
| astringent(adjective, hard, severe, sharp, rough) |
| blue(adjective, low, feelings, gloomy, miserable) |
| crotchety(adjective, tough, difficult, harsh, feelings) |
| down(adjective, hard, evil, rough, nasty) |
| embitter(verb, upset, turn, happy, poison) |
| glowering(adjective, sullen) |
| ill-natured(adjective, difficult, disagreeable, mood, angry) |
| irascible(adjective, difficult, irritable, touchy, sullen) |
| querulous(adjective, hard, difficult, critical, crabby) |
| sourness |