Saf is a slur used to describe South africans in a derogatory way. Abreviation of South Africa (commonly used in Britain).
The word Saf is a racial slur that has been used historically to degrade and dehumanize south africans. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to south africans. If you are unsure about whether or not it is appropriate to use the word Saf, it is best to err on the side of caution and avoid using it in any situation.