Synonyms for Reliable (same or very similar meaning)
WordNet sense 1 (worthy of being depended on):
dependable, honest, true
WordNet sense 2 (conforming to fact and therefore worthy of belief):
authentic
WordNet sense 3 (worthy of trust or belief):
trustworthy
WordNet sense 4 (tested and proved to be reliable):
tried
WordNet sense 5 (reliable in operation or effect):
certain, sure
From the ODE community, based on WordNet
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