Synonyms to unperfidious

tested, ascertained, assured, attested, certified, committed, confirmed, constant, decided, dedicated, dependable, determinate, determined, devoted, established, faithful, faithworthy, fast, fixed, guaranteed, in the bag, incorruptible, inviolable, made sure, nailed down, on ice, open-and-shut, proved, proven, reliable, responsible, secure, set, settled, stated, staunch, steadfast, straight, sure, to be trusted, tried, tried and true, true, trustable, trustworthy, trusty, unfalse, untreacherous, verified, warranted, calculable, fail-safe, firm, harmless, invincible, invulnerable, predictable, riskless, solid, sound, stable, steady, substantial, surefire, undangerous, unfailing, unhazardous, unperilous, unprecarious, unrisky, warranteed, well-founded, well-grounded, inco