: an expression of comparison comprising a usually well-known quotation followed by a facetious sequel
Named after a Dickens character—Sam Weller of The Pickwick Papers—this word is a cultural subcategory of word play. The character and his father were fond of this type of textual irony, enough so that readers coined the term after him. The example Merriam-Webster offers (from the original text) is: "'We'll have to rehearse that,' said the undertaker as the coffin fell out of the car." It took me a minute to get this—re-hearse. Okay. Some others:
"It all comes back to me now," said the Captain as he spat into the wind.
"So I see," said the blind man as he picked up his hammer and saw.
In a course I took last fall, the professor passed out a xerox handout about "Tom Swifties," another form of ironic word play, and apparently considered a sub-genre of the WELLERISM. The "Tom Swifty" is named after a a series of books with the same name (minus the suffix -y). In order to spice up the verb "said" after dialogue, the author began adding modifiers that punily complimented the action in the dialogue. Some random examples from the world wide web:
"I dropped the toothpaste," declared Tom, crestfallen.
"I've joined the navy," Tom said fleetingly.
"I've swallowed some glass," Tom mumbled painfully.
Such wit. Unfortunately, I am not at all witty today, so I will be leaving off with this information, and pausing before reflection ensues.