AGAIN: what is PERMAFROST?

FROST, as a concept, should be straight forward …

But what is the NEW DEFINITION of “permanent”? – seems like 2 years is permanent.

I WILL FUCKING SHOCK YOU: when I was in college 30+ years ago PERMAFROST meant PERMANENTLY FROZEN … it did not mean “frozen for a couple years at a time”.

WTAF is Permanent Permafrost?