1. Charged or energized with electricity: Be careful and don't touch that live wire.
2. Not imaginary, but actually existing and done in front of an audience; such as a play, a concert, etc. which is performed in front of people: The play had live music which made the drama more interesting.

The TV program provided live coverage of the political debate.

People thought the soldiers were using harmless blanks; however, they were shooting live bullets.