rep- we can replace your phone with a fru
customer- is it refurbished?
rep- well, it's actually certified like new
customer- so, refurbished?
rep- yes.
It is derived from a stupid misspelling and misinterpretation of a real word, "froufrou", meaning fancy trimmings, and it usually refers to women's clothing or a person's style of writing. It is not an adjective, although it is sometimes used as one.