WordNet sense 1 (a concave shape with an open top):

trough

WordNet sense 2 (the quantity contained in a bowl):

bowlful

WordNet sense 3 (a large structure for open-air sports or entertainments):

arena, stadium, sports stadium

WordNet sense 4 (a large ball with finger holes used in the sport of bowling):

bowling ball

WordNet sense 5 (a small round container that is open at the top for holding tobacco):

pipe bowl