(transitive) To move (something broad and loose) up and down. / (intransitive) To move loosely back and forth.

A loose filmy mass or a thin chiplike layer of anything / A scale of a fish or similar animal / (archaeology) A prehistoric tool chipped out of stone.

To break or chip off in a flake. / (colloquial) To prove unreliable or impractical; to abandon or desert, to fail to follow through. / (technical) To store an item such as rope or sail in layers

(UK) Dogfish. / (Australia) The meat of the gummy shark.

(UK, dialect) A paling; a hurdle. / A platform of hurdles, or small sticks made fast or interwoven, supported by stanchions, for drying codfish and other things.

(intransitive, obsolete) To flutter; palpitate. / (intransitive, UK dialectal) To hang loosely; flag. / (transitive, UK dialectal) To beat by flapping.

(Canada, US) A publicist, a publicity agent.

(Canada, US) To publicise, to promote.

Alternative spelling of flak.

Ground-based anti-aircraft guns firing explosive shells. / Anti-aircraft shell fire. / (figuratively, informal) Adverse criticism. / (informal) A public-relations spokesperson.