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

Five of her 10 children died in infancy, and both her husband and a grown daughter predeceased her.

From The Wall Street Journal • Apr. 11, 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

Unlike China, it had failed to institute a sweeping censorship system when the internet was in its infancy.

From The Wall Street Journal • Apr. 1, 2026

Leigh syndrome is a rare metabolic condition that affects the brain and muscles, usually appearing in infancy or early childhood.

From Science Daily • Mar. 31, 2026

Maya and Dilip give the boy a rattle and a baby book, with places for his parents to commemorate every possible aspect of his infancy.

From "The Namesake" by Jhumpa Lahiri

Related Words

• inception