The state or quality of being covered with or full of dust. The dustiness of the old attic made it difficult to breathe.
A measure of the amount of dust present in a particular environment or on a surface. The dustiness of the room was evident from the thick layer on the furniture.
The quality of being old-fashioned, dull, or lacking freshness and vitality (figurative). Critics complained about the dustiness of the syllabus, calling for more contemporary texts.