Nouns

(n)astuteness, profundity, profoundness, depth, deepnessthe intellectual ability to penetrate deeply into ideas
(n)deepness, profundity, profoundnessthe quality of being physically deep“the profundity of the mine was almost a mile”
(n)depth, deepnessthe extent downward or backward or inward“the depth of the water”, “depth of a shelf”, “depth of a closet”
(n)deepnessa low pitch that is loud and voluminous