Cool Nickname
If there’s one fatherly figure in the entirety of Guardians of the Galaxy that won’t be winning the Dad of the Year Award in this millennium, it’s Ego. We saw how Ego treated Star-Lord in both of the Guardians of the Galaxy films. Star-Lord ultimately winds up blowing his biological father’s brain to smithereens. Good riddance.
But how does Yondu, Star-Lord’s adoptive dad, feel about his biological father? Pretty much the same way his adoptive son does. Yondu uses a few harsh words when calling Ego, and he repeats the cool nickname in Vol. 2. That word is even mentioned in the MCU fandom website as Ego’s nickname.