>something that seems like truth, but is not truth - otherwise we'd just call it truth.

Not really. Something is verisimilar when it has the appearance of truth, or is likely to be true, regardless of whether it is in fact true. In Spanish, verosímil ('verisimilar') is rather frequently used in contexts in which one hypothesizes about the trueness of claims or statements, especially when it cannot be verified at that very moment, or ever.