A compulsion to set things on fire.
Antonyms: (couldn't really find any)
2) calm and not possessed
3) not crazy
1) Pablo likes to dress up as a disturbed santa and set people on fire in the bathroom because he is a pyromaniac.
2) Pablo goes to jail because he was a pyromaniac.
Setting Strangers On Fire Prank! - Bathroom Prank 2014
*Don't try this at home