Entry: base Pronunciation: 'bAs 1 n. a thing or part on which something rests; 2 adj. not honorable or moral; 3 v. to use as a base or basis for; ESTABLISH 1 Which sentence uses the word base as it is defined by definition 1? A. Sharon chose a gold base for the lamp. B. The judge based the decision on many facts. C. Kim will base her opinion on months of research. D. Gertrude's conduct was crude and base.