Synonyms and related words :
calculable, fail-safe, faithful, faithworthy, fast, firm, guaranteed, harmless, incorruptible, invincible, inviolable, invulnerable, predictable, proven, reliable, responsible, riskless, secure, solid, sound, stable, staunch, steadfast, steady, straight, substantial, sure, surefire, tested, to be trusted, tried, tried and true, TRUE, trustable, trustworthy, trusty, undangerous, unfailing, unfalse, unhazardous, unperfidious, unperilous, unprecarious, unrisky, untreacherous, warranteed, well-founded, well-grounded