His Japanese name, "Fumaretī", is probably derived from "fumareru" (踏まれる), which roughly means "stepped on". This is in reference to his enjoyment of having Foxy step on him.
"Treddon" is a play on "tread on", again relating to his submissive love of having Foxy step on him.
His German name "Zu Tritt" means "to kick", with "zu" also originally being a preposition only used by German aristocrats, in a similar way to "von". His name could also be a play on "zutritt" (access) to refer to his open attitude concerning the way Foxy can treat him.
His Spanish name "Sumisius" is a play on the word "sumiso", which means "submissive".
His Dutch name "Stephon" is a play on "step on", again referring to his submissive nature.