Do you know what a "wallflower" means?

Wallflower

1. 

1.) A person who because of shyness, unpopularity, or lack of a partner, remains at the side at a party or dance.

2.

2. 

2.) Any person that remains on or has been forced to the sidelines of any activity. 

It's interesting what kind of English words exist. :)

"He's a wallflower. You see things. You keep quiet about them. And you understand."
     Stephen Chbosky