A sex act in which your partner takes ice cubes into his/her mouth and performs a rim-job.
Dude 1: Hey man that girl Brenda is a freak!
Dude 2: Why do you say that?
Dude 1: She gave me a glacier rim bro!!
Dude 2: What is a glacier rim?
Dude 1: She had ice cubes in her mouth and she rimmed me, it was phenominal!