Synonyms to testify against

bear witness against, betray, blab, blow the whistle, fink, inform against, inform on, narc, peach, rat, sell out, snitch, snitch on, squeal, stool, tattle, tell on, turn informer, babble, back-fence gossip, be indiscreet, be unguarded, betray a confidence, blabber, blather, blether, blurt, blurt out, buzz, chatter, chitchat, clatter, cry, divulge, give away, gossip, gossiping, gossipmongering, gossipry, grapevine, groundless rumor, hearsay, idle talk, inform, jabber, leak, let drop, let fall, let slip, natter, newsmongering, piece of gossip, prate, prattle, retail gossip, reveal, reveal a secret, rumble, rumor, scuttlebutt, sing, spill, spill the beans, story, tale, talebearing, taletelling, talk, tattle on, tell, tell idle tales, tell secrets, tell tales, tittle-tattle,