second nature

American  

noun

1. an acquired habit or tendency in one's character that is so deeply ingrained as to appear automatic.

   Neatness is second nature to him.

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second nature British  

noun

1. a habit, characteristic, etc, not innate but so long practised or acquired as to seem so

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second nature Idioms  

1. A habit or mode of behavior so long practiced that it seems innate, as in Driving in heavy traffic is second nature to Chris. This expression is a shortened form of an ancient proverb, Custom (or usage) is a second nature, first recorded in 1390. It alludes to the fact that very frequently repeating something makes it seem completely natural or inborn.

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Etymology

Origin of second nature

First recorded in 1655–65

Example Sentences

Kwan said she would attend presentations with her sales team and rehearse what she saw in the mirror “over and over and over again” until it became second nature.

From MarketWatch • Jun. 23, 2026

But practice really does make it second nature — and the practice itself is, conveniently, delicious.

From Salon • Apr. 26, 2026

He added: "We need more male role models out there, talking about it and normalising it, so that it becomes second nature to all of us."

From BBC • Feb. 18, 2026

For example, cybersecurity training could teach simple, practiced routines and focus on creating habits, so that avoiding risky links becomes second nature.

From The Wall Street Journal • Dec. 9, 2025

But as the Egypt Game became second nature to its six participants, and they began to feel more and more at home in the land of Egypt, they gradually began to forget about being cautious.

From "The Egypt Game" by Zilpha Keatley Snyder