Not vigilant; unprepared; inattentive. / Unexpectedly or by surprise.

(slang, vulgar) To beat really badly.

Alternative spelling of jack of all trades

(idiomatic) To feel grumpy and irritable; to be easily annoyed.

(idiomatic) Verbal means of passing on information.

(algebra) The identity x²-y²=(x+y)(x-y), that holds for all real numbers.

Certain rules by which social intercourse is regulated among a social group, and which are founded on a regard for reputation.

(idiomatic, colloquial, UK) Used to terminate unwelcome lines of discussion

(idiomatic, dated) An ideal life of carefree prosperity and luxurious contentment.

A region of calm weather right in the middle of a storm. / (idiomatic) A period of calm in a tumultuous time.