The Rectus Abdominis is a long flat muscle that runs down the front of the abdomen. It is more commonly known as a six-pack on the body and can be seen in muscly/athletic people.
"WOW!!! your Rectus Abdominis is huge man, how do you get it like that?"
"You mean my six-pack?, just weight lifting"
"You mean my six-pack?, just weight lifting"
by monaro_waky August 4, 2006