A jerk or asshole; a mean or rude person; someone seen as being arrogant, snobby or obnoxious.
It's fine to help your friends eat healthy, but don't be a douchebag and harass them about it.
A sterile container which holds the fluid used for giving a vaginal douche.
Any social misfit; a doofus, dork, or nerd.
That pocket protector makes you look like a douchebag.