when a fat lady (particularly old), wears a swimsuit or bra that is too tight in the back and it squishes the back fat together to give the illusion that there are boobs on their back.
Lifeguard 1: "that old lady is large"
Lifeguard 2: "yeah man, look at her back cleavage, it's impressive."
Lifeguard 2: "yeah man, look at her back cleavage, it's impressive."
by erica elaine April 05, 2006
"That back of that girls dress is ridiculous! The plunging back line looks nice."
"Agreed, she has some nice back cleavage!"
"Agreed, she has some nice back cleavage!"
by cherrycord December 13, 2011