Synonyms of testifier

1 Syllable
proof
2 Syllables
gawkers, signer, viewers, affiant, witness, watcher, viewer, gawker
3 Syllables
witnesses, observer, deponent, attester, onlooker, attestant, attestor, looker-on, deposer, beholder, bystander, eyewitness, spectator
4 Syllables
signatory, rubbernecker, attestator, testimony
5 Syllables
corroborator, corroborators