dewlap

/ˈduːlæp/
noun
  1. A loose fold of skin hanging under the throat of some animals, such as cattle, dogs, or lizards.
    • The iguana's dewlap turned bright orange when it felt threatened.
    • The old bull had a large dewlap that swayed as it walked.
    • Some dog breeds, like the Bloodhound, have a prominent dewlap that helps trap scents.
Synonyms