Synonyms for Dyspeptic (same or very similar meaning)
WordNet sense 1 (affected by an impairment of normal physical or mental function):
ill, sickWordNet sense 2 (irritable as if suffering from indigestion):
atrabilious, bilious, liverishWordNet sense 3 (having an irritable and unpleasant disposition):
ill-naturedFrom the ODE community, based on WordNetadd/edit