someone who is the worst person, so much that they're as bad as several douches combined
"Ugh, I really hate him."
"I know right? He's such a douche canoe."
Someone so full of themselves, that they feel their physical appearance entitles them to to be admired. At which point, they then utilize this false sense of admiration to attempt to take advantage of infatuated victims.
That douche canoe thinks that just because he tries to impersonate Kurt Cobain, it automatically makes him a talented idol, when in reality he is an unskilled parasite.
your grade-a, classical fuck boy, typical douche who has earned the title of douche canoe
Huber, you're a fucking douche canoe! Stop looking up child pornography!
Someone, such as a business leader or head of school who makes a drastic change at the last minute that impacts the entire staff and gives 0 fucks about it.
T:"there is a safety issue with the building. What should we do?"
J:"extend the school year at the last minute of course!"
T:"perfect! Morale is low anyway, so fuck'em"
Staff:"wow....what a bunch of douche canoes"
A person who has exceeded the levels of douche bag and is not quite douchey enough to be considered an asshole.
Guy 1: Carl is such a douche bag!
Guy 2: That's an understatement, he's a douche canoe!