Obsolete form of upside down.

(idiomatic) Alternative form of look down on

(UK politics) The address of the residence in London of the Prime Minister of the United Kingdom. / (UK politics, by extension, metonymically) The title or office of the Prime Minister.

plural of anti-down quark

(idiomatic, of an event, thing, person) To emerge, come up; be about to happen; to approach or arrive on the scene; to present (itself or oneself).

Offering a seat to somebody.

(euphemistic, idiomatic) Synonym of go down the toilet: to fail.

(idiomatic, sports) To waste time at the end of a match such that it is terminated by running out of time, or during a match so a time penalty is made less severe.

(idiomatic, intransitive) To run down the clock.

(idiomatic) To set the standard.