infancy

American  

[in-fuhn-see] / ˈɪn fən si /

noun

plural

infancies

1. the state or period of being an infant; very early childhood, usually the period before being able to walk; babyhood.

2. the corresponding period in the existence of anything; very early stage.

   Space science is in its infancy.

3. infants collectively.

4. Law. the period of life to the age of majority, 21 years at common law but now usually 18; minority; nonage.

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infancy British  

/ ˈɪnfənsɪ /

noun

1. the state or period of being an infant; childhood

2. an early stage of growth or development

3. infants collectively

4. the period of life prior to attaining legal majority (reached at 21 under common law, at 18 by statute); minority nonage

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Etymology

Origin of infancy

From the Latin word infantia, dating back to 1485–95. See infant, -cy

Explanation

Infancy is the earliest part of a person's life, when they're a baby. It's extremely rare for anyone to remember their own infancy. An amazing amount of growth and development happens during infancy: babies learn to crawl, laugh, and communicate, among many other things. Infancy is vaguely defined, usually including the time from birth to about one year old. You can also use the word to mean "the very beginning of something," so if your lemonade stand is brand new, it's still in its infancy. The word comes from the Latin infantia, "early childhood," and literally, "inability to speak."

Example Sentences

Consider that around the time of the American Revolution, modern medicine was still in its infancy.

From The Wall Street Journal • Apr. 14, 2026

Although the technology remains in its infancy, there has been tremendous technical progress over the past year alone.

From Barron's • Apr. 10, 2026

When Ryder Paredes, 22, began studying computer science as an undergraduate three years ago, “AI was in its infancy, it wasn’t very intelligent,” the Montclair, N.J., native said.

From The Wall Street Journal • Mar. 22, 2026

The Good Friday Agreement had been signed just five years earlier and the Northern Ireland peace process was in relative infancy.

From BBC • Mar. 21, 2026

Johnny knew that it was no good omen that the old woman had no loyalty toward her mistress, whom she had known since her motherless infancy.

From "Johnny Tremain" by Esther Hoskins Forbes

Related Words

• inception