pentomino UK /pɛnˈtɒmɪnəʊ/US /pɛnˈtɑməˌnoʊ/ noun1 •A polyomino consisting of five square units. When packing pentominoes into three-dimensional shapes, the square units commonly are expanded into cubes instead of being flattened.If a domino had four squares on its surface, it would be a tetromino. With five squares, it would be a pentomino—nine, a nonomino, eleven, an unwieldy undecomino! — 2011 formspentominoes
