boat-shaped
/ˈbəʊtʃeɪpt/adjective
1Resembling a boat in shape. Frequently Botany.
2 Fashion. Designating a wide neckline on a garment, especially a dress, that sits just below the collarbone.
Origin
Mid 18th century; earliest use found in James Lee (1715–1795), nurseryman. From boat + shaped.