reliability; trustworthiness; dependability
Refers to the quality of being someone you can count on. Often used when describing a person's character or the feeling that someone is dependable.
He is a reliable leader.
That person isn't dependable, so I can't entrust important work to them.
Standard spelling using がい (value/worth) in kana. Common in everyday writing.
Kanji spelling for がい. Less common but still seen, especially in more formal or literary contexts.
Compound of 頼り (tayori, 'reliance') + がい (-gai, 'value/worth of doing something'). The がい suffix comes from 甲斐 (kai, 'effect/result'), indicating the worth or reward of an action.