danger line

1. 1.

   a line beyond which it is dangerous to go

   Broaderline

Questions about danger line

What does danger line mean?

danger line means "a line beyond which it is dangerous to go".

Is danger line a common word?

danger line is banded "Rare" — specialist or archaic — most readers will not have met it. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.