si·ren 
(s
īr
ən)
n.1. a. A device in which compressed air or steam is driven against a rotating perforated disk to create a loud, often wailing sound as a signal or warning.
b. An electronic device producing a similar sound as a signal or warning: a police car siren.
2. Any of several slender aquatic salamanders of the family Sirenidae of eastern North America, having external gills, small forelimbs, and no hind limbs.
[French sirène, from Old French sereine, Siren, from Late Latin Sīrēna, from Latin Sīrēn, from Greek Seirēn.]