Seems to me I mentioned these guys recently, but I’m too lazy to do a big search for my post about them (I think it was a post about buzzwords). Besides, this Dagwood oops Blondie comic is a good example of these words.
A portmanteau is an old kind of suitcase, usually made of leather, and usually with some kind of straps. You put unrelated things inside, hence the analogy with portmanteau words, parts of unrelated words put together into one word.
“Ever-popular” is just a plain old compound adjective.