for-
EN
[fɔː] [fə] Fpour-
FR for- 
- PréfixePREfor-
- (no longer productive) Meaning "far", "away"; "from", "out" e.g. forbid, forget, forsay; forbear, fordeem.
- (no longer productive) Meaning "completely", "to the fullest extent" e.g. fordo; superseded by combinations with "up" in senses where no upward movement is involved, e.g. forgive = give up (one's offenses), forgather = "gather up", forbeat = "beat up", etc.
- (dialectal) Very; excessively.
- forolded (“ very old ” )
- fornigh (“ very near ” )
- (no longer productive) Meaning "far", "away"; "from", "out" e.g. forbid, forget, forsay; forbear, fordeem.
Definition of for- in English Dictionary
- Partie du discours Hiérarchie
- Morphèmes
- Préfixes
- Préfixes improductives
- Préfixes improductives
- Préfixes
- Morphèmes
- fr for-
- en for-pay
- en for-real
- en for-than
- en for-profit
Source: Wiktionnaire
Grammaticalement, ce mot "for-" est un morphème, plus spécifiquement, un préfixe.