Adverbial has 2 senses

• densely(r = adv.all) dumbly, obtusely - in a stupid manner; "he had so rapaciously desired and so obtusely expected to find her alone"
• densely(r = adv.all) thickly - in a concentrated manner; "a thickly populated area"; "old houses are often so densely packed that perhaps three or four have to be demolished for every new one built"