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

Lucciano told the Britain's Got Talent judges his love for singing came from performing at care homes with his grandfather Frankie during school holidays.

From BBC • Apr. 21, 2026

The youngest hostage was a 9-month-old redheaded baby, and the oldest was an 86-year-old grandfather.

From The Wall Street Journal • Apr. 21, 2026

There’s a grandfather quality to Kani’s Sam, but the increase in years has only deepened the play’s poignancy.

From Los Angeles Times • Apr. 17, 2026

The 88-year-old's upcoming film, A Visit To Grandpa's, follows a young boy sent to spend a summer with his eccentric grandfather on a Welsh farm, surprised by the adventures he finds.

From BBC • Apr. 17, 2026

Christopher put his hand to his necklace, and his grandfather smiled a dry smile.

From "Impossible Creatures" by Katherine Rundell

Related Words

• ancestor
• grandpa
• patriarch