consume has 18 distinct synonyms spread across 4 of its 6 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its one recorded opposite is abstain.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
eat up completely, as with great appetite
“Some people can down a pound of meat in the course of one meal”
destroy completely
“The fire consumed the building”
engage fully
“The effort to pass the exam consumed all his energy”
Synonyms, antonyms and the broader and narrower relations for consume come from Princeton University’s WordNet. Full sources and licences.