Antonyms of adj dense

4 senses of dense

Sense 1
dense, heavy, impenetrable -- (permitting little if any light to pass through because of denseness of matter; "dense smoke"; "heavy fog"; "impenetrable gloom")

INDIRECT (VIA thick) -> thin -- (relatively thin in consistency or low in density; not viscous; "air is thin at high altitudes"; "a thin soup"; "skimmed milk is much thinner than whole milk"; "thin oil")

Sense 2
dense, thick -- (hard to pass through because of dense growth; "dense vegetation"; "thick woods")

INDIRECT (VIA impenetrable) -> penetrable -- (admitting of penetration or passage into or through; "a penetrable wall"; "penetrable defenses")

Sense 3
dense -- (having high relative density or specific gravity; "dense as lead")

INDIRECT (VIA heavy) -> light -- (of comparatively little physical weight or density; "a light load"; "magnesium is a light metal--having a specific gravity of 1.74 at 20 degrees C")

Sense 4
dense, dim, dull, dumb, obtuse, slow -- (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")

INDIRECT (VIA stupid) -> smart -- (showing mental alertness and calculation and resourcefulness)

Similarity of adj dense

4 senses of dense

Sense 1
dense, heavy, impenetrable -- (permitting little if any light to pass through because of denseness of matter; "dense smoke"; "heavy fog"; "impenetrable gloom")
       => thick (vs. thin) -- (relatively dense in consistency; "thick cream"; "thick soup"; "thick smoke"; "thick fog")

Sense 2
dense, thick -- (hard to pass through because of dense growth; "dense vegetation"; "thick woods")
       => impenetrable (vs. penetrable) -- (not admitting of penetration or passage into or through; "an impenetrable fortress"; "impenetrable rain forests")

Sense 3
dense -- (having high relative density or specific gravity; "dense as lead")
       => heavy (vs. light) -- (of comparatively great physical weight or density; "a heavy load"; "lead is a heavy metal"; "heavy mahogany furniture")

Sense 4
dense, dim, dull, dumb, obtuse, slow -- (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")
       => stupid (vs. smart) -- (lacking or marked by lack of intellectual acuity)