Chewing gum: a chewy candy meant to be chewed for flavor and texture (abbreviation of 'chewing gum').
授業の前にはガムを噛まないように注意された。
We were told not to chew gum before class.
試験中はガムを噛むと集中しやすいと言う人もいる。
Some people say chewing gum helps them concentrate during exams.
自動販売機でガムを買った。
I bought gum from the vending machine.
Gum: can also refer to rubber or sticky substances in certain contexts (i.e., 'rubber').
文房具店でガム糊（ガムのり）を買って封筒を閉じた。
I bought gum glue at the stationery store and sealed the envelope.
古いおもちゃのガム部分が劣化してボロボロになっている。
The rubbery/gummy parts of the old toy have deteriorated and are crumbling.
ガムテープは丈夫で、荷物の固定に便利だ。
Gaffer tape (often called 'gum tape') is strong and useful for securing packages.