cytosine cytoryctes • cytosome · · · Info · Definitions · Synonyms · Characters · · cytosine · · Text Latin · · Script 8 · · Length Definitions · · · (noun) a base found in DNA and RNA and derived from pyrimidine; pairs with guanine. Synonyms: C. · · Noun Definition 1 Synonyms · · · c · · Synonym 1 Characters · · c latin small letter c U+0063 e latin small letter e U+0065 i latin small letter i U+0069 n latin small letter n U+006E o latin small letter o U+006F s latin small letter s U+0073 t latin small letter t U+0074 y latin small letter y U+0079