A variation on the term "Effing and Blinding", meaning to swear or curse profusely. Used in the North of England, notably by one Karl Pilkington in an episode of the Ricky Gervais Show.
by AnaWanaMia? May 17, 2006
Means the same as effing (fucking), but has 'jeffing' on the end, for no other reason than it rhyming rather well.
by Lil' Alex January 13, 2009