I just tested it and this bit of JavaScript code should basicly achieve what you need:
var elementName = document.evaluate(' (//label[(text() = \'Name\' or . = \'Name\')]/parent::div)', document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
var elementNamenszusatz = document.evaluate('(//label[(text() = \'Namenszusatz\' or . = \'Namenszusatz\')]/parent::div)', document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
elementName.onmouseover = function(){
elementNamenszusatz.style.display = 'none';
};
elementName.onmouseleave = function(){
elementNamenszusatz.style.display = 'block';
};
This bit of code dynamically hides "elementNamenszusatz" when I hover with my mouse over "Name".
It's a bit buggy because the displaytype 'block' is wrong, but I'm sure you could make it work this way.