A grandfather is your parent's father: your mom's dad or your dad's dad. When your parent was growing up, their father was just “Dad” to them. Now that same person is your grandfather, connecting you to an earlier generation of your family.

Many grandchildren call their grandfathers by special names like Grandpa, Papa, Gramps, or Poppy. Some families use names from other languages, like Abuelo (Spanish) or Yeye (Mandarin Chinese).

Grandfathers often have more time and patience than they did when raising their own children. They might teach you to fish, help with homework, tell stories about what life was like when they were young, or share skills they've developed over decades. Some grandfathers are playful and silly, others are quiet and thoughtful, and many are somewhere in between.

The word also appears in the phrase grandfather clock, which refers to a tall, old-fashioned standing clock with a pendulum inside.

When a new law exempts something that existed before the law was passed, we say it's been grandfathered in. For example, if a city passes a rule that all restaurants must have parking lots, restaurants that existed before the rule might be grandfathered in and allowed to continue without parking.