WordNet sense 1 (worthy of being depended on):

honest, reliable, true

WordNet sense 2 (worthy of trust or belief):

trustworthy

WordNet sense 3 (consistent in performance or behavior):

rock-steady, steady-going

WordNet sense 4 (not subject to change or variation especially in behavior):

steady

WordNet sense 5 (financially sound):

good, safe, secure

WordNet sense 6 (financially secure and safe):

sound

WordNet sense 7 (tested and proved to be reliable):

tried

WordNet sense 8 (reliable in operation or effect):

certain, sure