inner side of a board; core side of sawn timber
Technical term in woodworking and carpentry; refers to the side of a board that was closer to the center of the log. Contrasts with 木表 (きおもて), the outer side.
See also: 木表
板の木裏は反りやすいので、使い方に注意が必要だ。
The inner side of a board tends to warp easily, so care is needed in how it is used.
木裏と木表を見分けるには
To tell the inner side from the outer side of a board, check the direction of the annual rings.
Compound of 木 (ki, 'tree, wood') and 裏 (ura, 'back, inner side'). The reading きうら follows standard rendaku-less compounding.