Able to be fixed, improved, or made right; something that has errors which can be mended.
From 'correct' plus the suffix '-able' (capable of), derived from Latin 'correctus' (made right) and Germanic suffix indicating possibility.
Correctable is an optimistic word—it assumes mistakes aren't permanent, which is why teachers love using it! It's the opposite of 'hopeless' and appears everywhere from typos to moral philosophy.
Complete word intelligence in one call. Free tier — 50 lookups/day.