Okay so I'm a dancer and in a routine we have to do this dance move. Basically you start on your knees and push into a backbend from that. Do you know what it's called? Thanks!

Dare I say it?....Ask your dance instructor that gave you the routine.

Possibly a Turkish backbend (Turkish drop?) Is this for belly dancing?

That isn't a dance move, but it isn't any belly dancing move I have ever seen because I do belly dancing for exercise. In fact, if I ever did that I wouldn't be able to get off my knees !

This is the move I thought the op might be talking about - maybe I'm calling it the wrong thing? I thought it was called a Turkish backbend, but I saw the term 'Turkish drop' as well...
http://brittabandit.files.wordpress.com/2011/07/turkishdrop.jpg
http://www.neareastdance.com/photos/NearEastDancePhotos/TurkishBackbendParis.jpg

Yes, I think odinn7 is right. Your routine dance instructor should answer that. Anyways, according to the description you gave, it looks to me as a spot on rachel brice turkish drop. Whoa!