standing for "triangle tits", a name given to a female possesing extremely large nipples, generally a breast to nipple ratio equal to or exceeding 2:1.
ie. nipple diameter is greater than or equal to half breast diameter
formula for double T's: nipple©ª ¡Ã breast©ª/2
easily found when wet or damp, white/faded/see-through swimming costumes or shirts are worn on German swimming teachers.
1. F***, check out that chicks double T's! they're huuuge!
"By the beard of Zeus! check out the Deep Pan Double T's on that fat sl*t!! Fair f***in' devans ayy!?"
"Carla is a lesbian."