red flag

English Thesaurus

1. something that irritates or demands immediate action (noun.act)

hypernym	:	annoyance, annoying, irritation, vexation,
definition	:	the act of troubling or annoying someone (noun.act)

2. the emblem of socialist revolution (noun.communication)

hypernym	:	allegory, emblem,
definition	:	a visible symbol representing an abstract idea (noun.communication)

3. a flag that serves as a warning signal (noun.communication)

hypernym	:	alarm, alarum, alert, warning signal,
definition	:	an automatic signal (usually a sound) warning of danger (noun.communication)

hypernym	:	flag, signal flag,
definition	:	a rectangular piece of fabric used as a signalling device (noun.communication)