Synonyms and related words :
calculable, dependable, faithful, fast, firm, incorruptible, invincible, inviolable, predictable, proven, reliable, responsible, secure, solid, sound, stable, staunch, steadfast, steady, straight, substantial, sure, surefire, tested, to be trusted, tried, tried and true, TRUE, trustable, trustworthy, trusty, unfailing, unfalse, unperfidious, untreacherous, well-founded, well-grounded