Some things cannot be undone.

(idiomatic) To reverse the irreversible; to perform the impossible.

The plant Sandersonia aurantiaca, native to South Africa. / Any member of the genus Blandfordia of flowering plants native to Australia. / Forest natal-mahogany (Trichilia dregeana)

(music) An enclosed spherical metal ball containing an unattached clapper with only a small slit opening, for higher pitched ringing.

(music, percussion) A percussion instrument consisting of a set of tuned metal tubes that are struck with a mallet.

A person, especially one of a group, who rings bells. / (derogatory) A door-to-door salesman.

A bell rung to give notice that buying and selling in a market may begin, or that it has ended.

A rope that rings a bell. / A handle attached to a rope that rings a bell. / The tail of a fox

A deep, usually rectangular, ceramic sink.

(idiomatic, informal) Digestive illness or diarrhoea, especially if suffered by a visitor to India.