This is the 5770th most frequent Japanese word.
なぞる
"なぞる" means "to trace or follow the outline."
Here, 'なぞる' is used to describe physically tracing along the lines of a map with a finger.
彼は指で地図をなぞりました。
He traced the map with his finger.
In this sentence, 'なぞる' is utilized for the act of following or outlining a drawing for better accuracy.
子供は絵をなぞって上手に色を塗りました。
The child traced the drawing and colored it skillfully.
'なぞる' here metaphorically means to write down or follow the content and structure of an explanation accurately.