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

Stories about friendships between animals must walk a fine line between the sweet and the saccharine.

From The Wall Street Journal • Mar. 20, 2026

They had to play this really fine line.

From Los Angeles Times • Jan. 29, 2026

“This is a fine line between boosting economic growth and boosting inflation.”

From MarketWatch • Jan. 26, 2026

One of the first things I learned in the hood is that there is a very fine line between civilian and criminal.

From "Born a Crime: Stories from a South African Childhood" by Trevor Noah