The quality or degree of being grainy; the presence of a granular or grain-like texture or appearance.
From 'grainy' plus the abstract noun suffix '-ness,' which converts adjectives into nouns describing qualities, states, or degrees.
Scientists measure graininess in photographs using a 'grain index'—digital cameras reduced graininess by using larger sensors, which is why modern phones can shoot in low light without the grainy look old cameras had.
Complete word intelligence in one call. Free tier — 50 lookups/day.