Tumblehome
Tumblehome or tumble home is the narrowing of a hull above the waterline, giving less beam at the level of the main deck. The opposite of tumblehome is flare.
A small amount of tumblehome is normal in many naval architecture designs in order to allow any small projections at deck level to clear wharves.
In automotive design, tumblehome sides taper inward as they go up. This includes a roof tapering in, and curved window glass.