1. swack up - Noun
2. swack up - Verb
swack up (third-person singular simple present swacks up, present participle swacking up, simple past and past participle swacked up)
(dated, Britain, school slang) To lie; to deceive; to take in.
swack-up (plural swack-ups)
(dated, Britain, school slang) A lie; a falsehood.
swack-up