nucleotide nucleoside • nucleus · · · Info · Definitions · Synonyms · Characters · · nucleotide · · Text Latin · · Script 10 · · Length Definitions · · · (noun) a phosphoric ester of a nucleoside; the basic structural unit of nucleic acids (DNA or RNA). Synonyms: base. · · Noun Definition 1 Synonyms · · · base · · Synonym 1 Characters · · c latin small letter c U+0063 d latin small letter d U+0064 e latin small letter e U+0065 i latin small letter i U+0069 l latin small letter l U+006C n latin small letter n U+006E o latin small letter o U+006F t latin small letter t U+0074 u latin small letter u U+0075