Most unknowable is an expression that refers to something that is difficult or impossible to understand or fathom. Its antonyms would be more familiar, understood, comprehensible, knowable, clear, and transparent. These words indicate that the subject matter is familiar or understandable. The opposite of unknowable may depend on the context in which the term is used. For instance, in math, the opposite of unknowable may be solvable. By providing antonyms for the expression, the reader can understand the range of meaning of the term and use appropriate vocabulary to relay a clear message.