English Dictionary
Definition red line in British English
red line noun
[countable] noun
/ˌred ˈlaɪn/
Red line has been used since the 1970s to denote a limit beyond which someone must not go without facing severe consequences. It suggests the idea of a physical boundary marking the limits between acceptable and unacceptable behaviour, and is related to expressions such as ’cross a line’ and ’draw a line in the sand’.
1
a statement, typically by a government, of acts that they regard as unacceptable and will respond to
Synonyms and related words
