Is there a name for a neologism that is close to an already existing word?

Solution 1:

In my research I unearthed the term corruption:

(Linguistics) an altered form of a word

It could also be a solecism:

A usage that constitutes a breach of the standard rules of grammar or syntax.

"Solecism" does however seem to pertain more to grammatical errors than the words themselves, so "corruption" is definitely superior in this scenario.

Solution 2:

I'd classify criminarily as a malapropism:

Malapropisms occur when someone substitutes a similar-sounding word for another word. For example, George Bush was reported to say, “nucular power pants” instead of “nuclear power plants” in 2003, and, in Sheridan’s play, Mrs. Malaprop said, “He's the very pineapple of politeness” instead of “He's the very pinnacle of politeness.”

It could very well be a portmanteau, as another answer mentions, but if so, it's one that's used in a malaprop way.

Solution 3:

It could also be a portmanteau of criminally and ordinarily. Seems like a comparison that Morrissey would do.