Put simply, "Bionicle" is a term which is never to be used to describe a character from said series, as it's only the name of the series itself. It's like calling Darth Vader "a Star Wars" - you just don't do it EVER.
Ah,I see.Although it isn't just the series name.The Toa,Turaga and Matoran are the Bionicle species.But meh.