(idiomatic, US, chiefly colloquial) Authorization that is extremely difficult to get, especially in a timely fashion. / (literally, US politics) A statute enacted by the United States Congress.

(genetics) Describing transcription factors that regulate the expression of genes on the same chromosome.

(genetics) Describing transcription factors that regulate the expression of genes on a different chromosome.

A comic pairing in which humor is derived from the uneven relationship between two partners, usually of the same gender, age, ethnic origin and profession, but often with drastically different personalities or behavior, maybe with a stooge or straight man.

(law, usually "an") Alternative spelling of act of God

(law) The doctrine, in European law, that cases involving a law with a reasonably obvious interpretation do not need to be referred to the European Court of Justice.

(informal) To become involved in something.

Something a person devotes their later life to, after retiring or quitting a former occupation.

(acting) An acting technique in which the actor fully immerses themselves into the character they are playing.

To participate in an activity, especially a successful or attractive one.