#menu {
  text-align: justify;
}
#menu:after {
  content: " ";
  font-size: 0;
  display: inline-block;
  width: 100%;
}
#menu > div {
  display: inline-block;
}

<div id="menu">
  <div>MENU ITEM</div>
  <div>LINK</div>
  <div>TWO WORDS</div>
  <div>ANOTHER</div>
</div>