Change Menu Name on Mobile Device

I have a vertical navigation menu on my website and when it’s viewed on a computer the categories look fine. By default, the theme I’m using (ET Origin) collapses the nav menu when viewed on a mobile device. I changed the css so it is now a horizontal menu and shows all the time but one of my categories has a long name (3 words) and it messes up the formatting of the menu. Is there any way for me to shorten or change the name of the category only when it’s viewed on a mobile device?

Thanks!