red flag

1.
Globalneutral
- A physical flag that is red in color, used as a signal or emblem.
2.
Globalneutralhistoricalpolitical
- A symbol of socialism, communism, or leftist revolutionary movements, historically associated with labor and political struggle.
3.
Globalneutral
- A literal warning sign indicating danger or hazardous conditions (for example, at beaches, construction sites, or roads).
4.
Globalinformalneutral
- A figurative indicator of a potential problem, danger, or cause for concern; a warning sign that merits attention.

Examples: