<center><style>a span{display:none;}
a:hover span {display: block;
position:absolute;
top:350px;
left: 350px;
width: 300px;
height: 300px;
padding: 0px;
margin: 10px;
z-index:6;
color:TEXT COLOR HERE ;
background-color:transparent;
font-size:50px;
font-family:Arial, text-align:center;}
</style>
<a href="http://URL_OF_SITE_HERE">DISPLAYED LINK TEXT HERE <span>APPEARING TEXT HERE </span></a>