/ ˈθɪnli; NAmE / adverb
1.
in a way that produces a thin piece or layer of sth :
Slice the potatoes thinly.
2.
with only a few things or people spread over a place so that there is a lot of space between them :
a thinly populated area
3.
in a way that is not sincere or enthusiastic :
She smiled thinly.
4.
in a way that does not hide the truth very well
SYN barely :
The novel is a thinly disguised autobiography.