O for Definition

for
prep

1. Intended to be given or sent to someone

Example: This is for you.
2. Towards.

Example: heading for home
3. Throughout (a time or distance).

Example: was writing for half an hour
4. In order to have, get, etc.

Example: meet for a chat
Example: fight for freedom
5. At a cost of something.

Example: said he'd do it for £10
6. As reward, payment or penalty appropriate to something.

Example: got seven months for stealing
Example: charge for one's work
7. With a view to something.

Example: train for the race
8. Representing; on behalf of someone.

Example: the MP for Greenfield
Example: speaking for myself
9. To the benefit of someone or something

Example: What can I do for you?
10. In favour of someone.

Example: for or against the proposal
11. Proposing to oneself.

Example: I'm for bed
12. Because of something.

Example: couldn't see for tears
13. On account of something.

Example: famous for its confectionery
14. Suitable to the needs of something.

Example: books for children
15. Having as function or purpose.

Example: scissors for cutting hair
16. On the occasion of something.

Example: got it for my birthday
17. Meaning.

Example: The German word for ‘help' is ‘helfen'
18. In place of; in exchange with something.

Example: replacements for the breakages
Example: translated word for word
19. In proportion to something.

Example: one woman for every five men
20. Up to someone.

Example: It's for him to decide
21. As being.

Example: took you for someone else
Example: know for a fact
22. With regard to something.

Example: can't beat that for quality
23. Considering what one would expect.

Example: serious for his age
Example: warm for winter
24. About; aimed at.

Example: proposals for peace
Example: a desire for revenge
25. In spite of something.

Example: quite nice for all his faults
26. Available to be disposed of or dealt with by.

Example: not for sale
27a. With reference to time: at or on;

Example: an appointment for 12 noon on Friday
27b. With reference to time: so as to be starting by;

Example: 7.30 for 8.00
27c. With reference to time: throughout (a time).

Example: in jail for 15 years

conj

1. archaic
Because; as.
Example: He left, for it was late

Idiom: as for

As far as concerns.

Idiom: be for it (be in for it)

colloq
To be about to receive a punishment, etc.
Example: You're for it now that he knows

Idiom: if it hadn't been for someone or something

Had they not intervened or had it not happened, then (some other course of events would have unfolded).

Idiom: O for

If only I had
Example: O for a pot of gold!

Etymology: Anglo-Saxon.