Source : Webster's Revised Unabridged Dictionary (1913)

Thickly \Thick"ly\, adv.
   In a thick manner; deeply; closely.

Source : WordNet®

thickly
     adv 1: spoken with poor articulation as if with a thick tongue;
            "after a few drinks he was beginning to speak thickly"
     2: in a concentrated manner; "old houses are often so densely
        packed that perhaps three or four have to be demolished
        for every new one built"; "a thickly populated area" [syn:
         {densely}] [ant: {thinly}]
     3: with a thick consistency; "the blood was flowing thick"
        [syn: {thick}] [ant: {thinly}]
     4: with thickness; in a thick manner; "spread 1/4 lb softened
        margarine or cooking fat fairly thickly all over the
        surface"; "we were visiting a small, thickly walled and
        lovely town with straggling outskirt" [ant: {thinly}]
     5: in quick succession; "misfortunes come fast and thick" [syn:
         {thick}]