Refers to a tree that is historically or culturally significant, often protected or designated as a natural monument. The kanji 名木 is especially common for this meaning.
This shrine has a famous old tree that is a thousand years old.
2
noun
excellent wood; precious wood; choice wood
Refers to high-quality, valuable wood used for fine furniture, crafts, or construction. The kanji 銘木 is often used for this sense, highlighting the wood's distinguished quality.
木材 is the general term for 'wood' or 'timber', without the connotation of excellence or rarity.
Etymology
Compound of 名 (めい, 'famous') or 銘 (めい, 'inscribed, distinguished') and 木 (ぼく, 'tree, wood'). The two kanji forms reflect the dual meanings: a famous tree and high-quality wood.