Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun red_flag

3 senses of red flag

Sense 1
red flag -- (a flag that serves as a warning signal; "we didn't swim at the beach because the red flag was up")
       => flag, signal flag -- (a rectangular piece of fabric used as a signalling device)
       => alarm, alert, warning signal, alarum -- (an automatic signal (usually a sound) warning of danger)

Sense 2
red flag -- (the emblem of socialist revolution)
       => emblem, allegory -- (a visible symbol representing an abstract idea)

Sense 3
red flag -- (something that irritates or demands immediate action; "doing that is like waving a red flag in front of a bull")
       => annoyance, annoying, irritation, vexation -- (the act of troubling or annoying someone)