Doubleheader and Duple

Doubleheader noun - Two games instead of one (especially in baseball when the same two teams play two games on the same day).

Duple and doubleheader are semantically related in two-fold topic. In some cases you can use "Duple" instead an adjective "Doubleheader".

Duple adjective - Consisting of or involving two parts or components usually in pairs.

Doubleheader and duple are semantically related in two-fold topic. You can use "Doubleheader" instead an adjective "Duple".