Synonyms and related words :
affirm, assay, attest, audit, authenticate, back, back up, balance, balance the books, bear out, bolster, bring to test, buttress, certify, check, check and doublecheck, check out, check over, circumstantiate, clench, clinch, collate, confirm, corroborate, cross-check, cut and try, demonstrate, document, double-check, essay, establish, experiment, fortify, give a try, give a tryout, guarantee, have a go, inventory, justify, overhaul, painstakingly match, play around with, practice upon, probate, prove, put to trial, ratify, recheck, reinforce, research, road-test, run a sample, sample, scrutinize comparatively, settle, shake down, show, strengthen, substantiate, support, sustain, take stock, taste, test, triple-check, try, try it on, try out, undergird, uphold, validate, vouch for, warrant