fine line

American  

[fahyn lahyn] / ˈfaɪn ˈlaɪn /

noun

1. a small, barely perceptible difference.

   There's often a fine line between helping and interfering.

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idioms

1. walk a fine line,

   1. to act carefully in order to avoid the wrong outcome or maintain a delicate balance.

      Moderators walk a fine line between censorship and protecting their site's users.

      I had to walk a fine line between maintaining the peace and doing my job.

   2. to act in a way that risks a disastrous outcome.

      You’re walking a fine line, buddy—if you don’t start watching your mouth, you’ll lose the respect of your kids.

Etymology

Origin of fine line

First recorded in 1845–50

Example Sentences

Now, that fine line has been given to the attacker.

From BBC • Mar. 31, 2026

As to the famous fine line between stupid and clever, the stupidity and the cleverness are all but inextricable, and to the point.

From Los Angeles Times • Feb. 20, 2026

Olympic coach, John Wroblewski, tells her, “Find that fine line, don’t get in trouble, don’t do anything stupid.”

From The Wall Street Journal • Feb. 16, 2026

There is a fine line between humility and confidence, but he said he can get a glimpse of that balance in the way candidates talk about their accomplishments.

From MarketWatch • Jan. 23, 2026

Lucky Strike always said there was a fine line between clever and stupid and laughed his head off every time he said it.

From "Ship Breaker" by Paolo Bacigalupi