Related Clues:

• Knot in a tree trunk
• The knotty problem of the back row
• Knot in wood that's coarse rejected
• Something sticking out of trunk giving rise to row
• Line up the knot
• Knot on tree inside trunk narrowed
• Knot turning up in Aran knitwear
• Burl in a tree
• Trunk knot
• Reversal of gross imperfection in timber