reliable

adjective

trustworthy, can be relied upon, able to be counted on

Wiktionary

Pronunciation: /ɹɪˈlaɪəbl̩/

adj

Etymology: Etymology tree English rely Proto-Indo-European *-tḗr Proto-Indo-European *-dʰlom Proto-Indo-European *-dʰlis Proto-Italic *-ðlis Latin -bilis Latin -ābilis Old French -ablebor. Middle English -able English -able English reliable From rely + -able.

Suitable or fit to be relied on; worthy of dependence, reliance or trust; dependable, trustworthy
“a reliable witness to the truth of the miracles”
“the best means, and the most reliable pledge, of a higher object”
Such that either a sent packet will reach its destination, even if it requires retransmission, or the sender will be told that it didn't.

noun

Something or someone reliable or dependable
“the old reliables”