A chewy, sticky wad of flavored sugar (or sorbitol or xylitol if it's sugar-free, smarty-pants) that may come as a ball, a stick, a cube, a 6-foot strip in a pink plastic dispenser, etc. Typically flavored as either classic bubblegum, a fruit (juicy fruit, strawberry, watermelon, orange, kiwi, pineapple,
dragonfruit, etc.), or some kind of mint (peppermint, spearmint, wintergreen,
winterfresh, sweetmint, smooth mint, polar ice,
fresh mint; the list goes on. What's the difference? Don't ask me.). Common uses include sticking it under desks, putting it in people's hair, playing with it as slime, using it as a currency/bribe, breath freshener, etc.
Person 1: You got any gum?
Person 2: Yes.
Mint gum. $1 per piece.
Person 1: What?! THAT'S SO -- Okay. *hands over dollar*
Person 2: Nice doing business with you. *takes dollar, then takes
chewed gum out of mouth and sticks it on
Person 1's hand*