noun
somewhere to go; place to go
Refers to a destination or a place one can head to; often used in negative or uncertain contexts like 行く当てがない (have nowhere to go).
彼は行く当てがなくて、公園のベンチで夜を明かした。
He had nowhere to go and spent the night on a park bench.
仕事を辞めたが、次の行く当てはまだ決まっていない。
I quit my job, but I haven't decided where to go next.
行き先 is a more general and neutral word for 'destination', while 行く当て often implies a place one can rely on or has in mind, frequently used in negative phrases.
Compound of 行く (iku, 'to go') and 当て (ate, 'aim, prospect'). The exact historical derivation is uncertain, but it functions as a noun meaning a place to go.