Pun
A play on words that exploits multiple meanings or similar sounds for wit or effect.
A pun turns on a word with two meanings or on words that sound alike, producing humor or a flash of double sense. Writers use puns for comedy, but also for irony and even tragedy when a character jokes while doom looms. The best puns carry serious weight beneath their playfulness.
Example
The dying Mercutio jokes that tomorrow he will be a “grave man,” punning on graveness and the grave even as he bleeds out.
Romeo and Juliet · William Shakespeare
See it in action
Analyses on StoryBites that use pun: