Old Scottish Sayings. It is British slang that’s used to tell someone you are going to bed. Example: Sometimes, I feel like voting doesn’t matter … British Slang Terms » Slang.org Perhaps the quintessentially British slang on the list. It’s like I’m going mental or something”. 50 useful English Slang expressions for a big night out! Beat the bishop – v – To masturbate. 27. nosh – food. Definition - a stupid or foolish person. a person who complains frequently. ‘goodnight’ is not a word. It is a phrase and is used everywhere English is spoken: ‘good night.’ 25. slag off – to insult or say rude things about somebody. 50 Awesome British Slang Terms You Should Start Using … how to say good 50 British Slangs You Need to Learn Immediately