noun
Loanword used as a noun for payment or salary, often in business or casual contexts.
今月のペイはまだ振り込まれていない。
This month's pay hasn't been deposited yet.
noun or participle which takes 'suru'
Used as a suru-verb. Often implies that an action or investment yields a worthwhile return.
この仕事はあまりペイしない。
This job doesn't pay off much.
広告費をかけた分は十分ペイした。
The advertising expense paid off well.
noun
Slang term for heroin, used in drug-related contexts.
警察はペイの密売ルートを追っている。
The police are tracking the heroin trafficking route.