How many syllables in dinosaur?

Definition of dinosaur:

dinosaur (noun):

any of numerous extinct terrestrial reptiles of the Mesozoic era.

any of a broader group that also includes all living and extinct birds

a decorative object or piece of furniture, of an earlier period, that is valued for its beauty, workmanship, and age

any of a group (dinosauria) of extinct, often very large, carnivorous or herbivorous archosaurian reptiles that have the hind limbs extending directly beneath the body and include chiefly terrestrial, bipedal or quadrupedal ornithischians (such as ankylosaurs and stegosaurs) and saurischians (such as sauropods and theropods) which flourished during the mesozoic era from the late triassic period to the end of the cretaceous period