reliance; dependence
彼は困ったときの頼りになる人だ。
He is someone you can rely on in times of trouble.
地図だけが頼りの山歩きだった。
It was a mountain hike where the map was our only guide.
唯一の頼りだった収入源が途絶えた。
The sole source of income I relied on was cut off.