A portmanteau of "poor man" and "portmanteau". Signifies a word that is a feeble attempt at creating a portmanteau or a feeble attempt at slang in general. It arises most often when someone consciously tries to come up with a slang word or phrase.
The linguistics professor knew much about language, but the slang he came up with was riddled with poormanteaus.
"Poormanteau" is clearly a poormanteau, and perhaps the only meta-poormanteau.