heel ‧ flip /ˈhiːlflɪp/ BrE AmE noun [countable]
a movement in ↑ skateboarding in which you push your heel down hard on the ↑ skateboard as you jump upwards off the board. The board turns around sideways in a complete circle and you land on it again when it has finished turning.
—heelflip verb [intransitive]