a device that makes a loud prolonged signal or warning sound

ambulance sirens

police sirens wailed

each of a number of women or winged creatures whose singing lured unwary sailors on to rocks

a woman who is considered to be alluring or fascinating but also dangerous in some way

Vanessa looked every inch the sultry screen siren as she posed for the cameras

an eel-like American amphibian with tiny forelimbs, no hindlimbs, small eyes, and external gills, typically living in muddy pools