Turtleback
Turtleback (tûr"t'l-bak`) , noun
1.
(Archaeol.) A rude stone celt of a form suggesting the back of a turtle.
2.
(Nautical) A convex deck at the bow or stern of a vessel, so made to shed the seas quickly.
Turtleback (tûr"t'l-bak`) , noun