(set phrase, colloquial) Suddenly, quickly, without warning.

(logic) Based on hypothesis and theory rather than experiment or empirical evidence. / Self-evident, intuitively obvious. / Presumed without analysis.

(logic) In a way based on theoretical deduction rather than empirical observation.

Alternative form of in two shakes

(logic) Involving induction of theories from facts. / (linguistics, of a constructed language) Developed on a basis of languages which already exist.

(logic) In a manner that deduces theories from facts.

(colloquial, idiomatic) Used with a comparative to express extreme heat or cold.

(US, idiomatic) So common as to be practically worthless.

(idiomatic, UK) So common as to be practically worthless.

(idiomatic) To be unable to recall a required piece of information. / (idiomatic) To fail; not to find anything; to produce no successful response.