Oxford Dictionary English red line nounnoun BrE BrE//ˌred ˈlaɪn// ; NAmE NAmE//ˌred ˈlaɪn// Add to my wordlistjump to other resultsan issue or a demand that one person or group refuses to change their opinion about during a disagreement or negotiations The issue of sovereignty is a red line that cannot be crossed.Check pronunciation: red line oxfordlearnersdictionaries.com
