1. Complete over-doing of something
2. A very fast motorhead song from 1979, It has the most badass drum into of any song... ever. Incidently, the drum intro was said to be "Overkill" as per the first definition by Motorhead's Bass Player / Singer Lemmy Kilmister.
1. Using a sledgehammer to swat a fly on your friends nose.
Only way to feel the noise is when it's good and loud,
So good you can't believe it's screaming with the crowd,
Don't sweat it, get it back to you,
Overkill! Overkill! Overkill!