eldest

American  

[el-dist] / ˈɛl dɪst /

adjective

1. oldest; firstborn; of greatest age: eldest sister;

   eldest brother;

   eldest sister;

   eldest born.

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eldest British  

/ ˈɛldɪst /

adjective

1. being the oldest, esp the oldest surviving child of the same parents

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Etymology

Origin of eldest

First recorded before 900; Middle English; Old English eldesta, superlative of eald, ald; see old

Explanation

Someone who's described as eldest in their family was born first. Your eldest sister is the oldest one. Use the adjective eldest when you're describing people in terms of birth order: the oldest is the eldest. Your eldest friend is older than your other friends. You can also use the word as a noun, meaning "firstborn." Your mom might introduce you by saying, "This is my eldest." It's a somewhat formal, old fashioned word, much less popular today than "oldest."

Example Sentences

Thai Princess Bajrakitiyabha Mahidol, the king's eldest daughter, has died aged 47, the royal palace announced Friday, more than three years after she was hospitalised following a sudden illness.

From Barron's • Jun. 12, 2026

The eldest of the siblings, who is now a teenager, has attended the vast majority of these cases.

From BBC • Jun. 10, 2026

Ten weeks later, he married a 30-year-old friend of his eldest daughter.

From The Wall Street Journal • Jun. 7, 2026

And there may be more good news on the way for the president’s eldest son.

From Salon • May 31, 2026

Eldred can choose any of his children for the throne, but he favors the three eldest: Balekin, Dain, and Elowyn—and Dain above the others.

From "The Cruel Prince" by Holly Black

Related Words

• earlier