(engineering) A helical ridge formed around a cylinder, or a helical groove formed around the inner wall of a bore, used mostly on fasteners and their connection points.

(biblical) A book of the Apocrypha.

Alternative form of threepenny bit

(historical) A former (pre-decimalisation) British coin worth three old pennies. / (Cockney rhyming slang) A woman's breast; a tit.

present participle of hang by a thread

(idiomatic) To be in danger, calling for precise caution; to be in a precarious situation.

simple past tense of throw the baby out with the bathwater

(games, racing) A race in which a team of two players are joined together at opposite ankles, and must complete a short sprint before the other teams.

(US) A bathroom with a toilet, sink, and shower stall but without a bathtub.

The basic education received in primary schools. Literally; reading, writing and arithmetic.