You become a ravehead when you're spending most of your time at raves and parties, or simply you just worship the hardstyle/hard house/techno/... music scene.
'Damn i'm turning into a ravehead.'
'Yeah i can see that u should spend more time with your mom lol.'
The face you make when you're expressing your opinion on something with a ton of rage.
This can also occur as a reaction to things happening outside of your power.