General:
* Slab
* Block
* Piece
* Square
* Section
* Pavement (for outdoor use)
* Mosaic (for small, decorative tiles)
Specific:
* Slate (for roofing or flooring tiles)
* Ceramic (for tiles made from clay)
* Terracotta (for unglazed ceramic tiles)
* Mosaic tile (for small, decorative tiles)
* Paver (for tiles used for paving)
* Shingle (for roofing tiles)
* Brick (for large, rectangular tiles)
* Flagstone (for flat, irregular stones used for paving)
Other:
* Tessellation (for a pattern of tiles)
* Checkerboard (for a pattern of alternating tiles)
* Grid (for a network of tiles)
The best synonym for "tile" will depend on the specific context and the type of tile you're referring to.