I also get a bit of a chuckle when I see these terms used in language documentation, along with "monomorphism" and other "math-y" terms. It just to me looks a bit like the authors are trying a bit too hard to appear very intelligent: sort of like a person who uses obscure vocabulary or complex grammar when communicating.
Alternatively, they know the words that a mathematician will understand, and realise that those words are the fastest and simplest way to get a mathematician to understand what is meant. Or perhaps the author is just not very good at aiming their words towards their target audience (if that target audience is not mathematicians).
What fraction of users of programming languages are mathematicians, or even CS graduates (of any degree level) who (should) care about the mathematical properties underlying the principles of the language? The answer: close to zero. The reason I chuckle is because I do understand the terms and I do recognize how absurdly placed they often are.
