difficult to use or handle or manage because of size or weight or shape; "we set about towing the unwieldy structure into the shelter"; "almost dropped the unwieldy parcel"
If you describe someone, especially a young person, as unmanageable, you mean that they behave in an unacceptable way and are difficult to control. The signs are that indulged children tend to become unmanageable when they reach their teens. = uncontrollable. difficult to control or deal with
If you describe something as unmanageable, you mean that it is difficult to use, deal with, or control. People were visiting the house every day, sometimes in unmanageable numbers. her freckles and unmanageable hair