A portmanteau of the slang word ‘blort’ (slang, vulg: meaning ‘to vomit, fart, ejaculate or otherwise expel matter from an orifice or use ill-considered words loudly') and portmanteau (a word created by the union of two or more words).
'I'm having a staycation.'
'What does that mean?'
'I'm having a holiday at home. Heard that little gem on NBC, thought I'd use it. Pretty cool huh?'
'It's a blortmanteau Bob...and as such, I now have to maim you.'
N.B. Blortmanteau is also a blortmanteau.