ToME: the Tales of Maj'Eyal

Cut Immunity: Is this resistance to slashing weapons and claws, or bleed effects, or what?

I don't see it displayed on the character sheet, is there a way to see my current cut immunity?

It's tied to the bleed effect. If you had any, it would show up with the immunities on the character sheet. I think some or both of the Undead races get cut immunity by default, too.

Skeletons are completely immune to cut, Ghouls are not. This is true of both enemy and player races.

Strangely, however, Bone Giants have no Cut immunity whatsoever...