noun. radially symmetrical animals having saclike bodies with only one opening and tentacles with stinging structures; they occur in polyp and medusa forms.
- phylum Coelenterata
- phylum Cnidaria
Example sentences of the word cnidarian
1. Noun, singular or mass
Living coral are the only species of cnidarian who don't need to catch prey for food, because they get most of their nutrients from symbiotic algae living inside them called zooxanthellae.
The tiny cnidarian got this name for its ability to regenerate from injury and bud off new individuals from its body.