echinoderm
echinoderm — noun
- echinodermsingular
- echinodermsplural
1. a sea animal whose body is built from five matching parts spread around a centra
a sea animal whose body is built from five matching parts spread around a central point, often with a hard, spiny outer surface; starfish and sea urchins are common kinds.
A starfish is an echinoderm, with five arms spread out around its middle.
defining pattern: [animal] is an echinoderm
Karim found a sea urchin, a spiny echinoderm, in a shallow rock pool.
apposition: a [adjective] echinoderm naming an example
Most echinoderms live on the sea floor and move using tiny tube feet.
Eve drew an echinoderm in her science book and labelled its five equal parts.
The museum tank held bright echinoderms, from orange starfish to black sea urchins.
用法筆記
Mainly a biology term — in everyday English, speakers usually name the specific animal (starfish, sea urchin, sea cucumber) rather than reaching for the group word.