Something like this?
var words = $('.words')[0]
$('#content').keyup(function(){
if (words == getSelectionStart()){
$(words).remove()
}
})
function getSelectionStart() {
var node = document.getSelection().anchorNode;
return (node.nodeType == 3 ? node.parentNode : node);
}
Example: http://jsfiddle.net/nickg1/ttMJW/1/