a berry is a fleshy fruit without a stone (pit) produced from a single flower containing one ovary. Berries so defined include grapes, currants, and tomatoes, as well as cucumbers, eggplants (aubergines) and bananas, but exclude certain fruits that meet the culinary definition of berries, such as strawberries and raspberries.
I am of the opinion that "a small, sweet, edible fruit" is closer to the right definition for the word, and that botanists' decision to appropriate the word for a redefined purpose was inappropriate and unnecessary.
First rule of accessory fruit club is, you do not talk about accessory fruit club. Second rule of accessory fruit club is, you DO NOT TALK ABOUT ACCESSORY FRUIT CLUB.
The taxonomy in biology can be really confusing.
Potatoes (only their fruits), peppers, cucumbers, eggplants, avocados, lemons, oranges, kiwifruit and papayas are also in the berry club.
Bananas have seeds, they're just incredibly degenerated in commercial bananas. Next time you have one, break off a chunk and count the black specks inside. Each one would've been a seed if not for generations of human intervention.