If it's the "-" on the keypad, I call it "minus". If it's the key on the main keyboard, I call it "dash".

I do it a little differently for the character (versus the key). That's probably more important because I'm almost always referring to the character, not the key. I call that a "minus", "hyphen", or "dash" depending on the context it's being used in.

The "ASCII" page in the Jargon File gives a few names for "-". It even says that the official ANSI/CCITT names are "hyphen" and "minus".

https://www.catb.org/jargon/html/A/ASCII.html

"Hyphen" in writing, "dash" or "tack" in command line

Minus is an option. Especially on numpad.

undefined

Dash

Minus

Dash. Sometimes - minus.

("-")