The French phrase rire dans sa barbe translates ‘to laugh in one’s beard’ meaning to laugh quietly about a past event. – WTF Fun Facts
Source: https://www.talkinfrench.com/weird-french-expressions-part-3/
WTF Fun Fact – Laughing In Your Beard

The French phrase rire dans sa barbe translates ‘to laugh in one’s beard’ meaning to laugh quietly about a past event. – WTF Fun Facts
Source: https://www.talkinfrench.com/weird-french-expressions-part-3/
no it mean “to laugh quietly without showing it”
“to laugh in your mind about something”