It means "permanent voraphilia". It's a fetish in which one fantasizes about being eaten alive or eating another creature permanently.
Usually, in roleplaying, permavore means that the characters being eaten will become unusable from now on. A character who has been prey in a permavore fantasy is considered "dead" by his creator and never used again.
— Yesterday, I use my character "Tobias" in a permavore fantasy.
— What a waste! ¿Can't you still use him?
— Nah, he's gone for good. It was a great character but it was worth it.
slip of the tongue perhaps,
Those idiots who drive around in a ridiculously raised pick up truck, making a top heavy vehicle even more top heavy and unstable
A:*gah*
B: "Whats the matter"
A: This dam prickup is blinding me.
B: Stupid thing's, as if there lights weren't blinding enough as it is.