What is the meaning of Nucleotide?

The monomer constituting DNA or RNA biopolymer molecules. Each nucleotide consists of a nitrogenous heterocyclic base (or nucleobase), which can be either a double-ringed purine or a single-ringed pyrimidine; a five-carbon pentose sugar (deoxyribose in DNA or ribose in RNA); and a phosphate group.

nucleotide

Source: wiktionary.org