effing and blinding using vulgar expletives; swearing.
☞ Effing and blinding here are euphemisms for taboo or vulgar slang words: effing represents the initial letter of fuck, and blinding reflects the now obsolete use of blind in mild curses (e.g. blind me, which became blimey).
2018Peter RobinsonCareless Love They were certainly a foul-mouthed pair, the Hadfield siblings.…Still, if Ronald Hadfield wanted to go around effing and blinding, who was she to complain?