入木三分 rùmùsānfēn penetrating Origin Definitions Defs Strokes Stroke Words Sentences Sents 入 rù verbparticle to enter to enter; to go into; to move from outside to inside木 mù noun wood (bound form) wood; timber; lumber三 sān numeral three the number three; 3分 fēn tenth a unit of length, area, or weight equivalent to one-tenth of the base unit