Так понятно?
<!DOCTYPE html>
<html lang="en">
<head>
<style>
.text_hide { padding: 10px; background-color: #eee; border: 1px solid red }
</style>
<script src="http://code.jquery.com/jquery-1.8.3.js"></script>
</head>
<body>
<button class="more">click</button>
<p class="text_hide">Lorem ipsum dolor sit amet, consectetur adipisicing elit. Veniam molestias sit, error tempore consequuntur quae velit ipsa ipsum recusandae molestiae exercitationem nisi ad doloribus quia, culpa incidunt veritatis laudantium non.</p>
<script>
$(".more").click(function(){
$(".text_hide").toggle(1000);
});
</script>
</body>
</html>