Reliance; something or someone to depend on; trustworthiness or a source of support.
彼は仕事の上で頼りになる同僚だ。
He is a reliable colleague at work.
頼りがなくて不安になる。
I feel uneasy without anything to rely on.
この書類は手続きの頼りになる証拠だ。
This document is reliable evidence for the procedure.