the father of your father or mother
"My grandfather taught me how to fix a bicycle when I was six years old."
A father of someone's parent.
"My grandfather taught me how to fix a bicycle when I was a child."
In plain English: A grandfather is your father's mother, which makes him your dad's mom? Wait, that's wrong. Let me try again. A grandfather is your parent's father. No, I need to stick to the prompt constraints strictly and ensure accuracy while being simple for a teen without examples or filler. Here is the correct definition: A grandfather is the male parent of one of your parents.
"My grandfather loves to tell stories about his youth while we eat dinner together."
To be, or act as, a grandfather to.
"The new safety regulations will grandfather in the existing factories to avoid forcing immediate closure and layoffs."
To retain discontinued laws or rules for (a thing, person or organization previously affected by them).
In plain English: To grandfather someone means to let them keep an old rule or benefit even after it has been changed for everyone else.
"He decided to grandfather his old car into the new inspection rules so he could avoid paying for an exhaust system replacement."
Usage: Use the verb "grandfather" when describing how old exemptions allow people or organizations to keep using outdated rules despite new regulations taking effect. This term specifically applies only to retaining privileges under previous laws, not to general exceptions or waivers.
The word comes from Middle English grandfadre, combining "great" and "father." It was likely influenced by the similar French phrase grand-père.