Definition of "Thickly" :

adverb: in a concentrated manner

"A thickly populated area."

adverb: in quick succession

adverb: spoken with poor articulation as if with a thick tongue

"After a few drinks he was beginning to speak thickly."

adverb: with thickness; in a thick manner

"Spread 1/4 lb softened margarine or cooking fat fairly thickly all over the surface."

adverb: with a thick consistency