Can't remove 'menu' item on menu

Hello,
on my website http://www.jiskahuizing.nl I use the Catch Everest theme and today I made a child theme so I could update the theme without it making changes to the layout of my website. I think I did that right and activated the child theme, but after this there appeared a menu item called ‘menu’ at the end of my menu bar and I can’t figure out how to remove it! This menu item doesn’t have a page and it links to my homepage. I already tried to make a custom menu and use that on the website, but also then the ‘menu’ item appears.
Does anyone know if this is a problem because I did something wrong while making the child theme or should I change something in the css file or something?