Pencil
noun
Your lead writing brush has lead in it. What kind of writing instrument has lead in it? How about a pencil?
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
そのパグは、このHBの鉛筆で描いたんだよ。
I drew the pug with this HB pencil.