/ ˈθɪkli; NAmE / adverb
1.
in a way that produces a wide piece or deep layer of sth :
thickly sliced bread
Apply the paint thickly in even strokes.
2.
thickly wooded, populated, etc. having a lot of trees, people, etc. close together
3.
in a deep voice that is not as clear as normal, especially because of illness or emotion