木材 (mokuzai) means “wood” | MotiTan Japanese Dictionary

More examples

木材でおもちゃを作ります。moku zai de o mo cha o tsuku ri ma su

I make a toy from wood.

家具には木材がよく使われます。ka gu ni wa moku zai ga yo ku tsuka wa re ma su

Wood is often used in furniture.

Means wood viewed not as a living tree but as a workable material for construction and manufacture.

材木zaimoku: Pieces of wood prepared for use in construction or manufacturing.

樹木から得られ、建物や家具などを作るのに用いる材料。ju moku ka ra e ra re tate mono ya ka gu na do o tsuku ru no ni mochi i ru zai ryō

The compound 木材 (mokuzai) consists of 木 (moku, "tree; wood") and 材 (zai, "material"), so its parts directly express material obtained from trees.

In building contexts, English speakers often use lumber for boards and wood for the material more generally, while 木材 (mokuzai) covers the wider category of usable wood.