dot matrix

/D AA1 T M EY0 T R IH0 K S/
noun
  1. 1

    A two-dimensional array or pattern of dots used (for example, by a display device or a printer) to represent alphanumeric characters and pictures.

noun
  1. 1

    A type of printer that prints characters using an array of small wires that produce an array of dots when striking the paper

Source: https://en.wiktionary.org/wiki/dot%20matrix, https://en.wiktionary.org/wiki/dot%20matrix%20printer