笑わず

without laughing

→ 笑う
笑わ laugh + Negative
verb Rare #27,516
without laughing A formal or literary negative form, meaning “without laughing” or “not laughing.”
JA: 彼は笑わずにその話を聞いていた。
EN: He listened to the story without laughing.
Conjugation of 笑う

彼女の冗談は笑わずにはいられない

You can't help laughing at her jokes.

彼女を笑わずにはいられない

I can't help laughing at her.