1. Of an electronic device, to lose or run out of power. My phone charged down during the flight, so I couldn't call my brother to let him know when I arrived.

2. In sports (especially rugby), to stop the forward progression of the ball with one's body. Their hopes for a late-game upset were foiled when they had their last-minute penalty kick charged down by the home team's star player.

3. noun In sports (especially rugby), the stopping of forward progression of the ball with one's body. In this usage, it is usually hyphenated or spelled as one word. A charge-down of their last-minute penalty kick foiled any hope they had for a late-game upset.