A bird that flies around in a circle endlessly until it finally flies up its own asshole.
You know what a hineybird is, don't you DJ? A hineybird is a bird that flies in circles, increasingly smaller concentric circles, until it disappears into its own behind. Poof! Mariotti's a hineybird.
by Hawk and DJ March 31, 2008
A womans vagina shape in tight pants
Hey mommy, how come you have a hiney were your bird should be ? Hence Hineybird.
by Captain clambake July 17, 2009