bong /bɒŋ $ bɑːŋ/ BrE AmE noun [countable]
[ Sense 1: Date: 1800-1900 ; Origin: From the sound ]
[ Sense 2: Date: 1900-2000 ; Origin: Probably from Thai baung ]
1 . a deep sound made by a large bell
2 . informal an object used for smoking ↑ cannabis , in which the smoke goes through water to make it cool