A Laugh, Laugh
noun
You know that 笑う is "to laugh." This is the noun version, because the う in 笑う turns to い (so don't confuse this as an adjective). What is the noun version of "to laugh"? It's a laugh.
わらい
The reading is the same as 笑う, so just make sure you know that so you can know this as well.
日本ではクリスマスディナーにケンタッキーを食べると言ったら、なぜか笑いが起きました。
Everybody laughed for some reason when I said that people eat KFC for Christmas dinner in Japan.
もう自分でも何を笑ってるのか分からないけど、ただ笑いが止まらないんです。
I don't know what I'm laughing at anymore, but I just can't stop laughing.
映画を見て泣くなんて、お前らしくないじゃないか。いつもどの映画のどんなシリアスなシーンにも大笑いしてるのに。
It’s not like you to cry at movies. You always laugh really hard when there are any serious scenes in them.