A guy who drops by an attractive girl's office desk in an attempt to hit on her. This guy will more than likely lean on the desk in an attempt to look cool and comfortable. In reality it looks pathetic.
Check out the leaner by Leanne's desk, does he really think he has a shot?
That guy is such a leaner.
Don't be such a leaner bro!
Quit leaning on that chick, you are ruining my chances.
Since you are new here, I'll let you in on a little secret, that guy over there is a leaner.