1 : being in a state of readiness to brood eggs that is characterized by cessation of laying and by marked changes in behavior and physiology <a broody hen>
“marked changes in behavior and physiology”
Basically the hens go baby crazy and does nothing but dote on their babies and viciously attack anyone who gets near their precious babies. That is broody. The general consensus that the only male protagonist who this describes is Batman with his brood of Robins, or possibly Wolverine of Marvel fame. It was also concluded that more truly broody male characters would not be a bad thing.