A nickname for the penis.
"Mark, quit tugging on your Brontosaurus in the theater!"
by CCOBB April 01, 2006
An incorrect name given to a sauropod skeleton. It was originally believed to be a new genus, but was later understood to be the same creature as the Apatosaurus.
Brontosaurus burgers couldn't have existed, correct?
by Diggity Monkeez March 17, 2005
A term used to indicate a very old person.
"That old hag's a friggin' brontosaurus!"
by Dave January 14, 2004
Some shit that doesn't exist because Apatosaurus killed it in its sleep.
Boobs? Ha, those are Brontosauruses, bra stuffer!
by Trololololium September 26, 2011