きり

alone, by oneself, since ... (with nothing happening afterward)

preposition Uncommon #14,571
alone, by oneself Often follows 一人 or 二人.
JA: 今日は一人きりで昼ごはんを食べた。
EN: I ate lunch alone today.
since ... (with nothing happening afterward) Follows the past form of a verb.
JA: 彼は朝出かけたきり、まだ帰ってこない。
EN: He went out this morning and still hasn’t come back.
Forms of きり
きりっきり

彼は若いので、まだそこへ一人きりでは行けない。

He's still too young to go there alone.

彼は病気でずっと床についたきりだ。

He has been bedridden with an illness.

ベンがいないけど朝出てったきり何かあった?

Ben isn't here—he left this morning and hasn't come back. Did something happen?

— ダーク・プレイス (2015)

これきりになさい

Let this be the last time.

— レベッカ (1940)

私はひとりきりで暮らすのはいやだ。

I don't want to live all by myself.

金曜に家を出たきり消息不明なの

They left home on Friday and haven’t been heard from since.

— サイコ (1960)

彼女はそこに一人きりだった。

She was all alone there.

これきりよ

This is the last time.

— アバウト・タイム ~愛おしい時間について~ (2013)

自分一人きりの状況を想像してごらん。

Imagine yourself completely alone.

だいぶ前に君を捜しにいったきりだ

It’s been quite a while since I went looking for you.

— ほんとうのピノッキオ (2019)

息子さんは週末も家でひとりきりだったとか…

I heard your son was all alone at home over the weekend...

— 大人は判ってくれない (1959)

独りきりの人生など耐えられない。

I can't bear a life all by myself.