free nipplin' 

to not be wearing a bra, therefore leaving your nipples free

"Omg Becky, im totally free nipplin' right now! Can you see them?"

free nipplin' by girls gone braless January 1, 2010

freenippin' 

When women go without wearing a bra under their shirt and their nipples become obviously noticeable. IE freeballing for women.

Look at that freenippin' skank. Her tits are sagging like an old maid.

freenippin' by ed74cj5 December 1, 2009