fine line

American  

[fahyn lahyn] / ˈfaɪn ˈlaɪn /

noun

1. a small, barely perceptible difference.

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

---

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

Tina says there's also a fine line between refreshing and overdoing it as "very aggressive ice exposure can irritate sensitive skin or trigger rosacea, so keep it gentle".

From BBC • Feb. 16, 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

Seoul has for decades trodden a fine line between China, its top trading partner, and the United States, its chief defence guarantor.

From Barron's • Jan. 4, 2026

“Good. It didn’t. Never fool yourself into perceiving things that don’t exist. It’s a fine line to walk, but sympathy is not an art for the weak willed.”

From "The Name of the Wind" by Patrick Rothfuss