Term for mis-use of a word, but on purpose...?

[Micky B]

Is there a word that describes the use of a word/phrase/abbreviation inaccurately, but knowing it is inaccurate, which in itself becomes generally accepted? For example if somebody enters a status on their Facebook and ends with #some-text - we all know the "hashtag" is a Twitter thing, not a Facebook thing, but it is acceptable to use this because we all understand its connotation. Often used to add humour to a message (#pointless-questions)

[GeneL]

Malapropism could be what you're looking for.

an act or habit of misusing words ridiculously, especially
by the confusion of words that are similar in sound.
http://dictionary.reference.com/browse/malapropism

the usually unintentionally humorous misuse or distortion of a
word or phrase; especially : the use of a word sounding
somewhat like the one intended but ludicrously wrong in the context
http://www.merriam-webster.com/dictionary/malapropism

[mildred f]

Neologism?

[Ben]

What about, "you misused that word"?

[Bilbo]

Satire would be most accurate in the sense that you describe - otherwise obtuse.

Malapropisms are unintentional (Mrs Malaprop believed she was using the correct word)
The comic effect is entirely Sheriden's.

[sheila26]

I agree with Mildred. A neologism, which is a newly coined term, word, or phrase, that is in the process of entering commonusagee, but has not yet been completely accepted into mainstream language.

[laduron7]

The word you are looking for is Catachresis. It's the use of a word that is obviously meant for another expression (such as a mixed metaphor) that is misplaced for humorous or dramatic effect.

[Hayley]

I would just call it a bastardisation of our language. Meh.