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

See Examples For:

fine line

Smith, who is based in Broadstairs, Kent, specialises in fine line and dot work tattoos.

From BBC ● Aug. 10, 2026

But there’s a fine line between being careful and being hidden.

From Slate ● Aug. 6, 2026

Research shows small talk can boost mental health, though there’s a fine line between friendly banter and oversharing.

From The Wall Street Journal ● Aug. 3, 2026

“With neighborhoods like this that are so densely populated, it is really always a fine line with how the businesses interact with the people who live here,” Mattei said.

From Los Angeles Times ● Jul. 17, 2026

Her name had been painted with great skill in red paint and outlined with a fine line of cream in a way that he would never have managed.

From "The Book of Dust: La Belle Sauvage" by Philip Pullman