もらい笑わらい

noun

infectious laughter; laughing because others are laughing

Describes the phenomenon of starting to laugh when you see or hear others laughing, even without knowing the reason. Often used in the phrase もらい笑いをする.

• 彼かの女じょが笑わらい出だすと、周まわりももらい笑わらいをしてしまった。

  When she burst out laughing, everyone around caught the laughter too.

• 会かい議ぎ中ちゅうにもらい笑わらいをこらえるのに必ひっ死しだった。

  I struggled to hold back infectious laughter during the meeting.