Convexo-concave and Helmet-shaped

Convexo-concave adjective - Convex on one side and concave on the other with the convexity being greater than the concavity.

Helmet-shaped and convexo-concave are semantically related. In some cases you can use "Helmet-shaped" instead an adjective phrase "Convexo-concave".

Helmet-shaped adjective - Having the convex shape of a helmet.

Convexo-concave and helmet-shaped are semantically related. You can use "Convexo-concave" instead an adjective phrase "Helmet-shaped".