second nature

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.

second nature

noun

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

Word History and Origins

Origin of second nature¹

First recorded in 1655–65

Idioms and Phrases

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.

Example Sentences

"It’s become second nature now to me and I can deal with the nerves and responsibility."

From BBC

"It’s actually strangely comfortable. It’s like second nature, if anything."

From BBC

So when it came to football, the hard work was second nature.

From Los Angeles Times

“It’s constant — it’s become second nature. That’s been great so far and I’m just excited to see where we can take it.”

From Los Angeles Times

The team was so familiar with each other that it was almost second nature when they walked out to the middle.

From BBC