It's unnecessary to specify float:left in your .tm dt, dd class since you have already set the display:inline. Hopefully, you are familiar with the concept of block & inline elements, where inline elements align horizontally and automatically form a single row...
CSS
.tm dt, dd
{
color:Black;
margin: 0;
padding: 0;
height: 30px;
line-height: 30px;
display:inline;
border:1px solid red;
}
.tm dt
{
padding: 0 5px 0 15px;
text-align: right;
opacity: 0.6;
width: 100px;
}
HTML
<div class="tm">
</dl>
<dt>Course </dt>
<dd>hello</dd>
<dt> Spl</dt>
<dd>hello</dd></dl></div>
Check out the demo:- http://jsfiddle.net/kude9/3/