Word square

Words can be read horizontally and vertically

A word square is a type of acrostic. It consists of a set of words written out in a square grid, such that the same words can be read both horizontally and vertically. The number of words, which is equal to the number of letters in each word, is known as the "order" of the square. For example, this is an order 5 square:

This keyword could refer to multiple things. Here are some suggestions: