Here's the breakdown:
* Tessella: A small square tile used in ancient Roman mosaics.
* Tessellatus: The past participle of the Latin verb "tessellare," meaning "to pave with tiles."
* Tessellation: The process of creating a pattern by fitting together identical shapes with no gaps or overlaps.
* Tessellate: To arrange in a tessellation pattern.
Therefore, the word "tessellate" ultimately comes from the ancient Roman practice of using small square tiles to create intricate mosaic patterns.