noun, noun which may take the genitive case particle 'no'
leaving to chance; drifting; happy-go-lucky
Describes an attitude or situation where one does not actively control the outcome, but lets events take their own course. Often used with 〜の or 〜にする.
See also: 成り行きに任せる (なりゆきにまかせる)
He lives a life of drifting, letting things take their own course.
We decided to travel without a plan, just going with the flow.
運任せ emphasizes leaving things to luck, whereas 成り行き任せ focuses on letting events unfold naturally without intervention.
Standard kanji spelling.
Variant with simplified 成行き.
Compound of 成り行き (course of events) + 任せ (leaving to). The exact historical derivation is uncertain, but the meaning is transparent from its parts.