chǎng, cháng
open space
Phonosemantic compound. 土 represents the meaning and 𠃓 represents the sound.
Evolution

Seal script
Shuowen (~100 AD)
Clerical script
Eastern Han dynasty (25-220 AD)Traditional script
ModernSimplified script
ModernDefinitions
chǎng
open space, field, market; large place used for a specific purpose; stage; scene (of a play); classifier for sporting or recreational activities; classifier for number of exams
cháng
threshing floor; classifier for events and happenings: spell, episode, bout
cháng
chǎng