What would you call a pc that puts expertise in a skill governed by his dump stat?

[Spacehamster]

Think about it, say a 8 INT rogue takes expertise in history, that makes him as good at history as a 20INT wizard. Kinda makes him a savant does it not? :)

[Atalas]

An idiot savant

[Daishain]

Don't think savant is the right comparison

Proficiency and expertise represent training in the skill in question. From context then, the Int 20 Wizard is remembering historical facts he heard in various conversations over the years, gleaned from the context of books he was reading, etc. and putting that data together thanks to his intellect. The Int 8 rogue worked his freaking arse off to study history, with painstaking hours spent fighting his tendency to misremember details.

So no, not a savant, just an idiot with a high enough work ethic to catch up to someone that didn't study at all due to just getting it.

[Ruslan]

A diligent student of history, taking notes all the time, going over his notes compulsively, cramming. Has absolutely no talent for the subject in question, but overcomes it with shear tenacity and huge investment of his time. One way to fluff it is that he can't remember any historical facts to save his life, but has tiny books of notes stuffed into every pocket, written in a shorthand script that only he can comprehend, to help him out when memory fails him.

[JellyPooga]

Think about it, say a 8 INT rogue takes expertise in history, that makes him as good at history as a 20INT wizard. Kinda makes him a savant does it not? :)

Some alternatives;

Str:8 Halfling with Expertise in Athletics - Just a halfling that can climb, jump and swim but is still physically small. (This one's pretty common for me)

Cha:8, Expertise in Intimidate - Classic unsocial Thug (useless at persuasion, deception or performance, but can still loom with the best of them.

Dex:8, Expertise in Sleight of Hand - good manual dexterity, but physically clumsy.

Wis:8, Expertise in Perception - Sharp eyes, but not a good judge of character or strong of will.

I don't know if there's a good single descriptor for any of these (or any others they might apply to), but they definitely fit certain character archetypes.