noun. a reptile of the order Chelonia.
- order Testudines
- anapsid reptile
- chelonian reptile
- order Chelonia
- archosaurian reptile
- Sphenodon punctatum
- diapsid reptile
Example sentences of the word chelonian
1. Noun, singular or mass
These creatures only live in freshwater or brackish water, so if you see a chelonian in a marine environment, it's definitely a turtle, not a terrapin.
When it senses danger or feels pressure upon its shell (called a carapace on top and plastron on bottom), a chelonian instinctively pulls its head, legs and feet inside the protective shell.