Definition of a fine line in English:

a fine line

A subtle distinction between two concepts or situations: there’s a fine line between humour and inappropriateness the president has been treading a fine line on immigration
More example sentences
  • In Riyadh, the absolute monarchy of Saudi Arabia walks a fine line to maintain power.
  • Each of them knows he walks a fine line.
  • In the Social Security debate, Democrats are walking a fine line.
See parent entry: fine