(sports) The portion of the playing area where one can legally play the ball, puck, etc. / The side of a vehicle on which the driver primarily propels it.

(US, idiomatic, slang, euphemistic) In secret. / (US, idiomatic, slang, euphemistic) Secretly sleeping with someone other than one's partner.

At the site of a job, or at the location of the customer of a product or service, as opposed to at the vendor's factory or office.

(informal, idiomatic) Enthusiastic for. / (informal, idiomatic) Knowledgeable about. / (informal, idiomatic) Skilled at.

Occurring in abundance; of a large quantity; many.

(idiomatic) To avoid failure only by good fortune.

(cricket, of a batsman) Having the weight on the back foot in order to play a defensive stroke / (idiomatic) in a defensive posture; on the defensive; off balance; at a disadvantage.

(transitive) to turn a switch to the "on" position in order to start or enable a device / (idiomatic) to change one's expression or appearance as if by turning a switch

(informal, Britain, Australia) Unacceptable or impossible.

(baseball) The circle drawn or painted on the field where the next batter to hit waits.