Dear @SL
Ok, sorry that my first option didnt work! :)
Remove that Custom CSS if you will and on the same Custom CSS & HTML Page but this time in 'custom <head> content add this code:
<script>
window.laytheme.on("newpageshown", function(layoutObj, type, obj){
jQuery(".menu-item-44 font").hover(function(){
jQuery(this).text("Welle");
}, function(){
jQuery(this).text("Teilchen");
});
jQuery(".menu-item-62 font").hover(function(){
jQuery(this).text("Teilchen");
}, function(){
jQuery(this).text("Welle");
});
});
</script>
Let me know how you go, apologies once again for the delayed response :)
Best
Richard