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

Alan Osmond, the eldest member of showbiz family the Osmonds and songwriter behind chart-topping hits including ‘One Bad Apple’ and ‘Crazy Horses,’ died Monday.

From Los Angeles Times • Apr. 27, 2026

Our only son, Hersh, our eldest child, had just turned 23 four days before.

From The Wall Street Journal • Apr. 21, 2026

His eldest sister Moneesha was a concert pianist; his sister Pamela a prima ballerina; and the youngest, Bunny, a regular voice on All India Radio.

From BBC • Apr. 17, 2026

Related: My former mother-in-law took out a life-insurance policy on my eldest child.

From MarketWatch • Apr. 14, 2026

But with the threat gone and his family arrived from Dresden, Tycho began to settle in at the castle, sending his eldest son back to Denmark to fetch four large observing instruments from Hveen.

From "The Scientists" by John Gribbin

Related Words

• earlier