laugh up (one's) sleeve

To try to hide that one is laughing at someone else. Ron may seem like a nice guy, but he laughs up his sleeve whenever he's around someone he dislikes. The popular kids laugh up their sleeves every time I walk by—it's so infuriating.

Common Names:

Name	Pronounced	Usage
Gwynn	-	Welsh
Elis	E-lis (Swedish)	Swedish, Medieval English
Sechnall	-	Irish
Corbett	['kɔ:bət]
Calfuray	kal-foo-RAW-ee	Native American, Mapuche
Emma	['emə]