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

During the early years of his leadership, Kim Jong Un sought to secure his legitimacy by dressing like his grandfather Kim Il Sung.

From BBC • May 5, 2026

His grandfather Antonio is revealed as a traveling merchant who operated between Catalan Spain and Morocco, rather than simply a farmer.

From Science Daily • May 4, 2026

The universe had taken my grandfather but had given me a new friend.

From Los Angeles Times • May 1, 2026

Edward “Ted” Crosby Johnson, who founded Fidelity Management & Research in 1946, and grandfather of FMR’s current CEO, Abby Johnson, worked as a lawyer at Ropes & Gray.

From Barron's • May 1, 2026

“But what about Fredrick’s grandfather? Surely he was a specimen of health.”

From "The Unseen Guest" by Maryrose Wood

Related Words

• ancestor
• grandpa
• patriarch