Definition of the Five-Hole
The five-hole is the space between a goalie's leg pads. The five-hole is literally the fifth hole/space that a goalie leaves open when he is in position in the net, the others being high glove, low glove, high stick side, and low stick side.
When a player shoots the puck through a goalie's five-hole and scores a goal, they say that he "went tweeners" – between the goalie's legs. Other terms used to describe a five-hole goal include "through the wickets" and "going fiver".