The term 'thin piece of wood' can be described by two crossword solutions: SLAT and SHIM. A SLAT is a thin, narrow strip of wood or metal used for various purposes such as in latticework, blinds, or furniture. A SHIM is a thin piece of material, usually wood, used to fill small gaps or spaces between objects. Both slats and shims are commonly used in carpentry and construction to provide support and stability.