Definition:Polyomino

Definition
A polyomino is a configuration of $n$ unit squares, for a given (strictly) positive integer $n$, which are placed side by side with vertices touching, to form a plane figure.


 * Polyominoes.png

A polyomino of $n$ squares can be referred to as an $n$-omino.

Also see
For small $n$, polyominoes have their own names:
 * $n = 1$: Monomino
 * $n = 2$: Domino
 * $n = 3$: Tromino
 * $n = 4$: Tetromino
 * $n = 5$: Pentomino
 * $n = 6$: Hexomino
 * $n = 7$: Heptomino
 * $n = 8$: Octomino