Lumber
Noun
もくざい
ひまだったら、木材をはこぶのを手伝ってくれない？
If you have nothing to do, can you help me carry some wood?
「木材」は、まだほとんど加工されていない原料としての木のことを指し、「材木」は、その木材を加工してすぐ使える状態に仕上げたものを指します。
"Mokuzai" refers to raw wood material that is not yet processed, and "zaimoku" refers to wood that is a finished product and can be used immediately.
二日なら時間を作れるよ。いつもの木材置き場で話さない？
I can make time on the second. Why don’t we meet up at the lumberyard and talk?
Wood that is lumber is lumber wood.
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.