Noun

1. A sharp or witty reply, or one which turns an argument against its originator.
2. A flask with a rounded base and a long neck that is bent down and tapered, used to heat a liquid for distillation.

   • 1893, A large curved retort was boiling furiously in the bluish flame of a Bunsen burner, and the distilled drops were condensing into a two-litre measure. — Arthur Conan Doyle, ‘The Naval Treaty’ (Norton 2005, p.670)

3. A container in which material is subjected to high temperatures as part of an industrial manufacturing process, especially during the smelting and forging of metal.

Verb

1. To say something sharp or witty in answer to a remark or accusation.
2. To make a remark which reverses an argument upon its originator.
3. To heat in a retort.