méng
swear
Phonosemantic compound. 皿 represents the meaning and 明 represents the sound.
Evolution

Oracle script
(~1250-1000 BC)
Bronze script
Early Western Zhou (~1000 BC)
Seal script
Shuowen (~100 AD)
Clerical script
Cao Wei (Three Kingdoms: 222-280 AD)Regular script
ModernDefinitions
méng
swear; oath, covenant, alliance; oath; pledge; union; to ally; league, a subdivision corresponding to prefecture in Inner Mongolia
Sources