ill-natured
sour
acerb
acerbate
acerbic
acescent
bearish
bilious
bitter
cankered
choleric
crab
crabbed
cranky
cross-grained
crotchety
dry
dyspeptic
embittered
green
jaundiced
ornery
pickled
pungent
sec
sour as vinegar
sour-tempered
soured
sourish
tart
tartish
unripe
unsweet
unsweetened
vinegary
waspish