look up any word, like guncle:
 
1.
over-the-top, unappealing (often of behaviour), crass, distasteful
Queen Latifah's leopard-print boob tube at the Grammy Awards was overboard, man!
by Kiran P October 27, 2005
 
2.
When you done banging a chick on a bunk bed, and she wants to cuddle, you kick her bitch ass off the bed so you can have the whole damn thing to yourself.
When I was through with Amy I overboarded her.
by Brian October 12, 2004
 
3.
A type of relationship were two people are not married. The couple is beyond the relationship status of boyfriend/girlfriend but don't adhere to cultural norms of marriage.
Heather and Ryan are in a Overboard relationship.

We don't believe in marriage, we are overboard.

Kurt Russell & Goldie Hawn
by GameBoy09 December 30, 2013