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"
incapable of or resistant to bending; "a rigid strip of metal"; "a table made of rigid plastic"; "a palace guardsman stiff as a poker"; "stiff hair"; "a stiff neck"
designating an airship or dirigible having a form maintained by a stiff unyielding frame or structure
not changeable or subject to change; "a fixed and unchangeable part of the germ plasm"-Ashley Montagu; "the unchangeable seasons"; "one of the unchangeable facts of life"
marked by unjust severity or arbitrary behavior; "the oppressive government"; "oppressive laws"; "a tyrannical parent"; "tyrannous disregard of human rights"
weighing heavily on the senses or spirit; "the atmosphere was oppressive"; "oppressive sorrows"