N1
たなり・なり
While... ~ing, Remaining, Not or ever since, Keep or leave
父が釣りにいったなりまだ帰ってこない、大丈夫かな...
My father hasn't come back home since he went out fishing. I wonder if he is okay…
Explanation
「たなり・なり」 has 2 uses
1Stays that way
After an action, the person stays in that position or state, not moving or speaking.
彼は腰かけたなりじっと考えていた。
While remaining seated, he has been pondering intently.
レース後、草の上に横になったなり、泣き続けた。
After the race, he cried while lying down on the grass.
2Never followed up
After doing something, what should come next never happens: someone left and never came back, or met once and never got in touch.
弟は彼女に振られて部屋に入ったなり、全然部屋から出てこなくなってしまった。
Ever since my brother locked himself in his room after his girlfriend broke up with him, he hasn't come out of his room at all.
父が釣りにいったなりまだ帰ってこない、大丈夫かな...
My father hasn't come back home since he went out fishing. I wonder if he is okay…