- George: "Yeah, well, I've never picked a fight in my entire life."
- Marty: "Look, you're not going to be picking a fight, Dad... Dad... Dad... Daddy-o. You're coming to her
[Lorraine's] rescue, right?"
- — The exchange between George and Marty
"Daddy-o" was a friendly term used in 1955 by teenage boys towards their friends.
Marty McFly used this term to hastily cover up a slip of the tongue he made, when he called his future father George "Dad" at one point while George was hanging his family's clothes on a clothesline in the backyard of the McFly residence.