grandfather

American  

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

noun

grandfathers plural

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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Other Word Forms

Noun Inflected Forms

• grandfathers
  plural

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

Attacking midfielder Christian Pulisic’s grandfather was a Croatian emigrant.

From The Wall Street Journal • Jun. 22, 2026

According to family lore, my policeman grandfather was on duty at Yankee Stadium on the evening of June 22, 1938, when he started chatting with a man from out of town.

From The Wall Street Journal • Jun. 18, 2026

Much of the crowd was in their 60s, 70s, and 80s, supporting Schlossberg in large part because they remember his grandfather.

From Slate • Jun. 18, 2026

Using Class B voting shares, he kept nearly as tight a grip on Ford Motor as his grandfather had.

From Barron's • Jun. 17, 2026

And there it was, pretty much the worst punishment his grandfather could have laid down.

From "Half Upon a Time" by James Riley

Related Words

• ancestor
• grandpa
• patriarch