From the all-time classic movie, "Fletch". Underhill is the prick member at the tennis club that has his lunch bill run up to $400 by Fletch ordering caviar, lobster thermidor, and Dom Perignon.
"Put it on the Underhill tab".
by Napan August 17, 2006
Reference to "under the hill", underhill means more or less opposite of "over the hill" or to be dead. Underhill means to be godlike, invulnerable, and elite.
The noob got pwned by the underhill player.
by 1337machine1337 April 28, 2008
a funny looking troll with a mushroom cut that lives under a bridge. It is a urban legend but I think it is true
OMG that underhill scared me
by LilJOnwhattt: July 11, 2005
to cum in a shot glass and drink it like its alcohol.
Bencic likes to drink his underhill
by LilJOnwhattt: July 19, 2005