Definition of sirenian
: any of an order (Sirenia) of aquatic herbivorous mammals (as a manatee, dugong, or Steller's sea cow) that have large forelimbs resembling paddles, no hind limbs, and a flattened tail resembling a fin
Origin of sirenian
New Latin Sirenia, from Latin siren
First Known Use: 1883
Learn More about sirenian
Britannica.com: Encyclopedia article about "sirenian"
Seen and Heard
What made you want to look up sirenian? Please tell us where you read or heard it (including the quote, if possible).