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

EU trade ministers meeting in Brussels Friday trod a fine line, stressing that the EU-China relationship was important, but more balance was needed.

From Barron's • May 22, 2026

But the staff must walk a fine line in dealing with customers.

From The Wall Street Journal • May 6, 2026

Carriers are walking a fine line between strong demand and rising costs, and they’re responding the only way they can in the short term: fewer flights.

From MarketWatch • Apr. 21, 2026

But it has walked a fine line over six weeks of war in the region, describing open waters in the strait as of global interest, while avoiding any condemnation of Iran’s assertion of control.

From Los Angeles Times • Apr. 12, 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