丸材 is read as まるざい (maruzai) and means log.
まるざい
maruzai
まるたざい
round timber
まるい
curved
まるみ
mellowness
まるまる
entirely
まるめる
to lump together
まるほん
reciter's book
まる
circle
まるで
as if
to become rounded
まるっきり
completely
まるた
dace (Tribolodon hakonensis)
まるめこむ
to roll up and put into (something)