Definition:Order of Matrix/Also known as

Order of Matrix: Also known as
The order of a matrix can also be referred to as its dimensions, but the term dimension has a different, deeper meaning in linear algebra and this may be a source of confusion.

Some sources refer to the size rather than order, which is acceptable enough.

Some sources do not bother to give the order an actual name, merely referring to, say, an $n \times m$ matrix.