adverb (r)

• spoken with poor articulation as if with a thick tongue(adv.all)

  Example:
  After a few drinks he was beginning to speak thickly.
  

  source: wordnet30
• in a concentrated manner(adv.all)

  Example:
  A thickly populated area.
  

  Synonym:
  densely
  Antonym:
  thinly
  

  source: wordnet30
• with a thick consistency(adv.all)

  Synonym:
  thick
  Antonym:
  thin, thinly
  

  source: wordnet30
• with thickness; in a thick manner(adv.all)

  Example:
  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.
  

  Antonym:
  lightly, thinly
  

  source: wordnet30
• in quick succession(adv.all)

  source: wordnet30
• In a thick manner; deeply; closely.(adverb)

  source: webster1913