decomposeEnglishOxford American Thesaurusdecompose verb 1 the chemical prevents corpses from decomposing: decay, rot, putrefy, go bad, go off, spoil, fester, perish, deteriorate, degrade, break down, break up, molder; technical mortify, necrotize, sphacelate; archaic corrupt. 2 some minerals decompose very rapidly: break up, break apart, fall apart, fragment, disintegrate, crumble, dissolve; break down, decay. 3 semantic markers decompose the meanings of words into more primitive elements: separate, divide, break down, dissect, atomize, dissolve, resolve, reduce; rare fractionate.