Echinoidea echinoid • echinologist · · · Info · Definitions · Characters · · Echinoidea · · Text Latin · · Script 10 · · Length Definitions · · · (noun) sea urchins and sand dollars. Synonyms: class Echinoidea. · · Noun Definition 1 Characters · · E latin capital letter e U+0045 a latin small letter a U+0061 c latin small letter c U+0063 d latin small letter d U+0064 e latin small letter e U+0065 h latin small letter h U+0068 i latin small letter i U+0069 n latin small letter n U+006E o latin small letter o U+006F