(politics, UK, New Zealand, often attributive) In a house of legislature following the model of the Westminster system (such as the UK House of Commons), any bench behind either of the front benches and occupied by rank-and-file members.

(of a gun, cannon, Bunsen burner, etc.) To fire in the opposite direction, for example due to an obstruction in the barrel.

(firefighting) Alternative spelling of back fire

To make spiteful slanderous or defamatory statements about someone. / (informal) To attack from behind or when out of earshot with spiteful or defamatory remarks.

One who engages in backbiting; a backbiter.

Any pain or ache in the back.

A decorated cloth hung at the back of a stage. / An image that serves as a visual background. / The setting or background of an acted performance. / (figuratively) Any background situation.

(transitive) To serve as a backdrop for.

A backhanded stroke or blow. / (swimming) A stroke swum lying on one's back, while rotating both arms through the water as to propel the swimmer backwards.

To swim the backstroke.