Definitions by JonnyPMN30

ATR 

Arm-to-Tit ratio.

The proportion of a woman's breast size to the width of her arm in profile.
Skinny arms to larger breast are preferred. 1:2 or 1:2.5 is generally considered ideal.

"Look at that athletic waitress with the nice rack. She has great ATR."

ATR by JonnyPMN30 May 31, 2024