[Twenty Sixteen] Edit the Mobile Menu Button Text

I’m using the Twenty Sixteen theme (a child theme of it) and need to modify the mobile menu button. Presently, the button says ‘Menu’, and I’d like to replace that text.

I did discover the js/functions.js file which seems to handle a lot of the button’s behavior, but I didn’t see a way to modify the button label text itself in that file.

Can someone point me in the right direction?

Thanks.