crack a smile
to smile, usually only slightly or unwillingly

[TahlilGaran] Dictionary of Contemporary English ▲

crack a smile
[informal]
to smile, especially when you do not feel like smiling.
The man barely cracked a smile at his friend's joke.
(usually negative)

[TahlilGaran] English Idioms Dictionary ▲

crack a smile
to let a smile show on one's face; to smile a little
Our boss never cracked a smile during the meeting.

I tried not to crack a smile during the speech.

[TahlilGaran] English Idioms Dictionary ▲

crack a smile
v. phr., informal To let a smile show on one's face; permit a smile to appear.
Bob told the whole silly story without even cracking a smile.
Scrooge was a gloomy man, who never cracked a smile.
When we gave the shy little boy an ice cream cone, he finally cracked a smile.

[TahlilGaran] English Idioms Dictionary ▲