Why are invertible matrices called 'non-singular'?

Question

Where in the history of linear algebra did we pick up on referring to invertible matrices as 'non-singular'? In fact, since - the null space of an invertible matrix has a *single* vector - an invertible matrix has a *single* solution for every possible $b$ in $AX=b$ it's easy to imagine that that invertible matrices would be called 'singular'. What gives?

Answer 1

Interesting question that i didn't know the answer to at first, but i think this is it:

https://www.dictionary.com/browse/singular

"Singular" leans more towards meaning unique or special, rather that being based off the word "single". I agree that it's a misleading name, but you can also call them noninvertible or degenerate matrices instead.