densest

1. permitting little if any light to pass through because of denseness of matterExamples: "dense smoke"; "heavy fog"; "impenetrable gloom"Synonyms: dense, heavy, impenetrable

2. hard to pass through because of dense growthExamples: "dense vegetation"; "thick woods"Synonyms: dense, thick

3. having high relative density or specific gravityExamples: "dense as lead"Synonyms: dense

4. slow to learn or understand; lacking intellectual acuity; ; ; - ThackerayExamples: "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"Synonyms: dense, dim, dull, dumb, obtuse, slow