William N. answered 04/11/19
Fifty Years Experience in American Sign Language and Interpreting
It would be best if you posted a video showing the sign but from what you describe it appears to be the sign CONTINUE/STILL. There is a dictionary based in handshapes that let's you look up signs based on handshapes. It is called the Handshape Dictionary. Look it up. I'm not sure if it is still in print.