look up any word, like sparkle pony:
 
1.
An erection of the nipples.
"OMG my nipples are hard, it a nipplerection!"
by Justin J. L. August 18, 2006
 
2.
To administer a nipple or nipples rectally.
"The nipplerection in that porn movie nearly made me shit myself."
by somethingplex1 December 11, 2011