grandfather

American  

[gran-fah-ther, grand-] / ˈgrænˌfɑ ðər, ˈgrænd- /

noun

1. the father of one's father or mother.

2. a forefather.

3. the founder or originator of a family, species, type, etc.; the first of one's or its kind, or the one being longest in existence.

   the grandfather of all steam locomotives.

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verb (used with object)

1. to exempt (something or someone) from new legislation, restrictions, or requirements.

   The law grandfathered all banks already operating at the time of passage. He was grandfathered into the pension plan.

grandfather British  

/ ˈɡrænd-, ˈɡrænˌfɑːðə /

noun

1. the father of one's father or mother

2. (often plural) a male ancestor

3. (often capital) a familiar term of address for an old man

4. dialect a caterpillar or woodlouse

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Etymology

Origin of grandfather

late Middle English word dating back to 1375–1425; see origin at grand-, father

Explanation

Your grandfather is the father of one of your parents. If your grandfather is quite old and has dozens of grandchildren, it might be hard for him to remember your birthday every year. Everyone has two biological grandfathers, whether they've had the chance to know them or not. In some families, grandmothers and grandfathers are involved in raising and caring for their grandchildren, while in others a grandfather may have died or live very far away. Informally, a grandfather can also be someone who started or invented something: "Blues musician Robert Johnson was the grandfather of rock and roll."

Example Sentences

Neighbor Karen Banuelos told The Times that the grandfather of the children spoke to another neighbor and revealed what happened.

From Los Angeles Times • Jun. 2, 2026

“But I’d never seen anyone that looked or sounded like my grandfather in it. I realized that it could be a really creative method to preserve his voice and his story. “

From Los Angeles Times • May 29, 2026

On a September night in 1961, Hill's grandfather Barney and his wife Betty believed they were abducted by aliens as they returned home from vacation.

From Barron's • May 29, 2026

They were cheered on by hundreds of spectators in the park, and crossed the finish line accompanied by friends and family including sister Kennedy Frampton, while dad John and grandfather Glenn also watched on.

From BBC • May 28, 2026

At the other side of his cave stood the grandfather clock tocking away.

From "The Very, Very Far North" by Dan Bar-el

Related Words

• ancestor
• grandpa
• patriarch