from Latin pransōrius pertaining to breakfast (from prandēre to breakfast) + -ous
Note: historically, dinner referred to the first meal of the day, and was generally eaten around noon-time;
it is sometimes still used for a noon-time meal, but dinner as the evening meal is standard in many English-speaking countries
1656 - Glossographia, Thomas Blount;
"Pransorious, of or belonging, or serving for dinner"