Check in woodworking - crack along the wood's annual growth rings, not passing through the entire thickness of the wood.
Knot or knothole in woodworking - A tight knot is usually not a problem; a loose or dead knot, surrounded by a dark ring, may fall out or may have already left a hole.
Shake in woodworking - separation of grain between the growth rings, often extending along the board's face, and sometimes below its surface.
Split in woodworking - crack going all the way through the piece of wood, commonly at the ends.
Wane in woodworking - missing wood or untrimmed bark along the edge or corner of the piece.