This is a bit like
naped, that I accepted recently. It's almost always used in combination with a number:
five percenter,
one percenter. Hence some of the Oxford dictionaries list it with a hyphen in front, and identified as a combining form. But at the same time, some of the examples given by those dictionaries show the term used without a hyphen. And some dictionaries (Collins, Wiktionary, Dictionary.com) list it as a normal word.
Wiktionary gives a second meaning, as a slang term for an agent, but it appears they were only able to come up with one usage example, from a 1944
Billboard article, so I'd rate that usage extremely rare.
I think I should go along with the dictionaries that list it, and accept it as a rare word.
An example from the
WalesOnline site in April 2022:
I just think he’s class. He’s exactly what a team needs, a hundred percenter who’s aggressive on both sides of the ball and has an all-round confrontational game that’s top-drawer.
(Quite a few recent usages in the news are referring to the Three Percenters (usually capitalised, and hence not pertinent for our purposes). This is a far right movement whose name is based on the dubious proposition that it took just three percent of the population of the American colonies to win American independence.)
