How to say "timber" in Japanese

• 木材もくざいJLPT N2approx.Common
  nounThe broad word for wood or timber as a material — lumber in general, whatever it is destined for. When 'timber' just means the stuff itself, this is the natural choice.
  この古ふるい家いえは木材もくざいでできている。↗

  This old house is made of wood.
• 材木ざいもくJLPT N2approx.Common
  nounTimber or lumber in the concrete sense: wood cut for use in building. Use it when 'timber' points to actual construction stock rather than wood as an abstract material.
  ひろしは材木ざいもくをひいて板いたにしています。↗

  Hiroshi is sawing the wood into boards.
• 木きJLPT N5approx.Common
  nounAt bottom this means 'tree'; as 'wood' it denotes the raw material rather than processed lumber. For 'timber' in the building sense it is seldom the word you want.
• 用材ようざいCommon
  nounTimber considered as material for practical use — wood destined to be worked into something. It is narrower than 木材, which remains the safer choice for general references to timber.

For timber as a material in general use 木材; for lumber cut for building use 材木; 用材 is a narrower term for timber as usable material; 木 really means 'tree' and seldom fits.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 木材もくざいlumber
• 材木ざいもくwood (for building)
• 材ざいwood
• 用木ようぼくtimber
• 木きwood
• 用材ようざいlumber