cromulant 

Not simply used to refer to a frequently used word as per the use in "a perfectly cromulent word" but may be better defined as germane, or apt, synonomous with appropriate, or fitting.
This defintion suits both uses in The Simpsons' famous episode.

"a perfectly cromulent word"

"he has just embiggened the office of town crier with that cromulent speech"

cromulant by RathminesPimp October 26, 2004

cromulant 

abundantly used, proliferate, widespread, accepted

It's a perfectly cromulant word

cromulant by Matt Parker (parkman47) November 13, 2002

cromulant 

Over use of spray paint. Particularly many different colours seen together.

The graffiti was a cromulent and nauseating disgrace.

cromulant by Brett Burton April 22, 2003

Cromulent 

Used in an ironical sense to mean legitimate, and therefore, in reality, spurious and not at all legitimate. Assumes common knowledge of the inherent Simpsons reference.

Yes Professor Smith, these citations are perfectly cromulent. chuckle

Cromulent by Bradley Yeats, Professor of Linguistics March 15, 2003

comulate 

communication during copulation. specifically referring to sexual requests/feedback during sex. such as: "HARDER", "DON'T STOP", "YES! Right there!", "a little to the left", "grab my ass", "that's not my clit", and any such instructions.

sex with you is so much fun, i love the way you comulate!

comulate by Chucked1 January 16, 2016

credulant 

A person who is too credulous and just believes everything they see on the internet.

Stupid credulants, clogging up Facebook with all their hoaxes and virus warnings and stuff. Why don't they just think for a bit first?

credulant by Bdoserror October 26, 2011

Cumulant 

A sperm cell that was underdeveloped and somehow won the race

Bro 1: Yo bro you look like a cumulant.
Bro 2: I have 98 chromosomes.

Cumulant by retardBloke42 March 8, 2022