Anapsida anapsid • anapsidan · · · Info · Definitions · Characters · · Anapsida · · Text Latin · · Script 8 · · Length Definitions · · · (noun) oldest known reptiles; turtles and extinct Permian forms. Synonyms: subclass Anapsida. · · Noun Definition 1 Characters · · A latin capital letter a U+0041 a latin small letter a U+0061 d latin small letter d U+0064 i latin small letter i U+0069 n latin small letter n U+006E p latin small letter p U+0070 s latin small letter s U+0073