The Collaborative International Dictionary of English v.0.48:
nucleotide \nucleotide\ n. a phosphate ester of a nucleoside; one of the monomeric components of DNA or RNA. [WordNet 1.5 +PJC]WordNet (r) 3.0 (2006):
nucleotide n 1: a phosphoric ester of a nucleoside; the basic structural unit of nucleic acids (DNA or RNA) [syn: nucleotide, base]