Epistemicism is a position about vagueness in the philosophy of language or metaphysics, according to which there are facts about the boundaries of a vague predicate which we cannot possibly discover.
Given a vague predicate, such as 'is thin' or 'is bald', epistemicists hold that there is some sharp cutoff, dividing cases where a person, for example, is thin from those in which they are not.
As a result, a statement such as "Saul is thin" is either true or false.
Epistemicism gets its name because it holds that there is no semantic indeterminacy present in vague terms, only epistemic uncertainty.
You can help Wikipedia by expanding it.This linguistics article is a stub.