(of airspace) In which aircraft are forbidden to fly. / (of people) Who are forbidden to board an aircraft.

(physics) A random signal (or process) with a flat power spectral density; a signal with a power spectral density that has equal power in any band, at any centre frequency, having a given bandwidth.

A small mug, cup or ladle. / (dated outside dialects) A small measure of spirits equivalent to a gill. / (slang) The head.

(Of a company or organization) providing goods or services but not for the purpose of making a profit.

A not-for-profit company or organization.

Not functioning properly. / Of a place, not to be entered.

Alternative form of no go

An airspace in which aircraft, especially military aircraft, are forbidden to fly.

(carpentry) A wooden block, the size of a brick, built into a wall, as a hold for the nails of woodwork. / (carpentry) One of the square logs of wood used in a pile to support the roof of a mine.

(transitive) to fill in, as between scantling, with brickwork. / (transitive, shipbuilding) to fasten, as shores, with treenails.