Also used as its acronym kit, keep it together is a self motiviational phrase to use when things are getting chaotic and you are starting to freak. It is meant to be said repeatedly and very quickly, almost as one word.
"Keep it together, keepittogether, keepittogether...."
A person who is intimidated by large groups of people and is therefore afraid to speak. This person will hardly ever say a word, but will laugh with the group and look interested. However, this person will be very talkative outside of a large group of people.
Uh-oh, Tatiana has Chelsea Syndrom. She hasn't said a word all day.