slow to learn or understand; lacking intellectual acuity; "so dense he never understands anything I say to him"; "never met anyone quite so dim"; "although dull at classical learning, at mathematics he was uncommonly quick"- Thackeray; "dumb officials make some really dumb decisions"; "he was either normally stupid or being deliberately obtuse"; "worked with the slow students"
having high relative density or specific gravity; "dense as lead"
hard to pass through because of dense growth; "dense vegetation"; "thick woods"
permitting little if any light to pass through because of denseness of matter; "dense smoke"; "heavy fog"; "impenetrable gloom"
being changed over time so as to be e.g. stronger or more complete or more useful; "the developed qualities of the Hellenic outlook"; "they have very small limbs with only two fully developed toes on each"
(of real estate) made more useful and profitable as by building or laying out roads; "condominiums were built on the developed site"
(used of societies) having high industrial development; "developed countries"