A widow/widower who sleeps with several people to satisfy the erotic needs that their dead spouse can't fulfill anymore.
Typically has sex with younger, hotter people who they would never actually settle down with.
Melissa: Dang girl! How many guys have you slept with since your husband died?
Jenny: At least 8 or more. I guess I'm a Widhoe now!
Usually a term used in place of the popular "windows", namely by people who prefer other operating systems, but have have some kind of way to use certain windoes only programs.