A term used to describe having sex with someone who is large or has less than desirable physical qualities. It was coined one night when a invitation was sent out to join a party with a "extra large" sorority. When considering to accept said invitation, a man we will simply call JJ calmly said "lets do it, lets tank the whale".
So i went to that girls house the other night and we started to get it on until her room mate walked in and totally saw me tanking the whale.
by Thom Burney November 03, 2007