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A word used by Lily in "How I met your mother".

It means: a mutant combination between cockroach and mouse.
Robin: So what was it, a cockroach or a mouse?
Lily: It was a cockamouse!
Robin: What?
Lily: It's some sort of mutant combination of the two.
It's as if a cockroach and a mouse, you know...
by Mythdra March 28, 2009
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