The most common use of a firework is as part of a fireworks display (also called a fireworks show or pyrotechnics), a display of the effects produced by firework devices. Fireworks competitions are also regularly held at a number of places.
A gourd is a plant of the family Cucurbitaceae, particularly Cucurbita and Lagenaria or the fruit of the two genera of Bignoniaceae calabash tree, Crescentia and Amphitecna. The term refers to a number of species and subspecies, many with hard shells, and some without.
Though there was some connotation I learned of several years ago of gourmand being someone who consumed food in excess, that was certainly, in my history of reading about food, a secondary definition and not the main one.