newborn

American  

[noo-bawrn, nyoo-] / ˈnuˈbɔrn, ˈnyu- /

adjective

1. recently or only just born.

2. born anew; reborn.

   a newborn faith in human goodness.

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noun

plural

newborn, newborns

1. a newborn infant; neonate.

newborn British  

/ ˈnjuːˌbɔːn /

adjective

1. 1. recently or just born

   2. ( as collective noun; preceded by the )

      the newborn

2. (of hope, faith, etc) reborn

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Etymology

Origin of newborn

Middle English word dating back to 1250–1300; see origin at new, born

Explanation

A newborn is literally a baby animal (including us human animals) who was born in the past month. Figuratively, newborn describes anything recently born or created, like a newborn interest in vocabulary. Little babies are newborns until they're a month old — four weeks is the official human newborn cut-off age. Then they’re just regular ol’ babies. Other things can be newborn as long as they’re brand new — a newborn restaurant was opened recently, a newborn celebrity might be 18 but she just got famous. You could have a newborn fear if you recently became scared of something. Most newborns are not scary, though. (Unless you’re babysitting one.)

Example Sentences

They exposed newborn mice to low-oxygen conditions similar to altitudes above 13,000 feet for about a week.

From Science Daily • Apr. 15, 2026

Marc, known to family and friends as “Tiger,” had been working to build an accessory dwelling unit at the family’s Santa Ana home, where he planned to live with Loera-Zarco and their newborn.

From Los Angeles Times • Apr. 3, 2026

He left a wife and five children, including a newborn.

From The Wall Street Journal • Mar. 24, 2026

As your circumstances require, you can add a newborn child, change your profession, update your bank-account information, put in a new address or add a business.

From MarketWatch • Mar. 23, 2026

He purred with Gray under his silver mother’s rough tongue, tasted her warm milk, felt the weight of her chin resting over his newborn skull.

From "Pax" by Sara Pennypacker