red line
Uncrossable moral threshold
A red line is a boundary that must not be crossed—a limit beyond which consequences follow.
The phrase comes from the literal practice of drawing red lines on maps or documents to mark prohibited zones.
In diplomacy and negotiation, crossing a red line triggers serious response: The president declared that using chemical weapons would be a red line.
To redline (one word) historically meant to outline areas on maps where banks refused loans, typically discriminating against minority neighborhoods.
Maximum allowed extent
- thresholdPoint of beginning
- demarcationFormal boundary setting
- borderOuter edge or limit
- barrierObstruction preventing passage
restriction · prohibition · constraint · cap · ceiling · maximum · ultimatum · tripwire
limit
Maximum allowed extent
- thresholdPoint of beginning
- demarcationFormal boundary setting
- borderOuter edge or limit
barrier · restriction · prohibition · constraint · cap · ceiling · maximum · ultimatum · tripwire · trigger
- hockey rink partsboards, glass, plexiglass, crease, penalty box
- rail linesA train, D train, L train, Crossrail, scenic railway
- hockeypuck, hockey, ice hockey, pucks, field hockey
- limitslimit, limits, limitation, upper limit, lower limit
- linesparallel lines, intersecting lines, dotted, dashed, curved
- Negotiation Termsdeadlock, bargaining, negotiation, stalemate, compromise
red linesuggestion
Idea proposed for consideration
guideline · recommendation · preference · wish · open door
red linenon-issue
Matter of no importance
nice-to-have · low priority · afterthought · footnote · small potatoes
red linesuggestion
Idea proposed for consideration
request · hint · gentle nudge · trial balloon · feeler