To Paint
To Plaster, To Lacquer, To Spread
Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means paint and the verb vocab version is to paint and to plaster and to lacquer.
ぬる
Let's put a new (ぬ) layer of paint on the wall. Then we'll plaster it.
マニキュアを塗り終わってからまた電話してもいい？
Can I call you back when I finish painting my nails?