for-
/fɔː(r)/prefix
1
- denoting prohibition表示“禁止”：
forbid.
2
- denoting abstention, neglect, or renunciation表示“戒除”, “忽视”, “放弃”：
forgive
forget
forgo
3
- used as an intensifier［用于强调］：
forlorn.
词源
Old English.