backheel

Short definition from Wiktionary

Noun

1. 1
   A kick played by the heel which typically travels in the opposite direction from which the player is facing.
2. 2
   A method of tripping or throwing by getting the leg back of the opponent's heel on the outside and pulling forward while pushing his body back.

Verb

1. 1
   To perform such a kick.
2. 2
   To perform such a trip or throw.