(of the construction of a ship) not having castles, flush-decked. Also race-building.

Of a vessel: Having no erection above the flush deck.

Having a poop deck, esp. of a specified kind. Chiefly in high-pooped adj.

fitted with a spar-deck.

Of a ship: having a well-deck.

having a back like a turtle's; furnished with a turtle-back (sense 1).

attributive or as adj. Furnished with a whaleback (sense 1); of the shape of the back of a whale.