A surname originating as a patronymic.

A surname.

(mathematics, catastrophe theory) The point at which a slow, reversible change becomes irreversible, often with dramatic consequences.

present participle of tip it down

The practice of leaving a tip (gratuity). / The act by which something is tipped or inclined. / The dumping of rubbish.

present participle of tip

(chiefly US) A fictional pastime wherein a person sneaks up on a sleeping cow and pushes it over.

plural of tipping point

present participle of felt-tip

The illegal dumping of rubbish on unauthorised sites.