Cytidine is a

Explanation:

As seen from the above structure, cytidine has a cytosine group which is a nitrogenous base, attached to the five membered ribose ring. The linkage occurs through the glycosidic bond. Thus, it is a nucleoside.

Nitrogenous base: They are the compound which contain N atoms and act as a base.

Nucleotide: Compound in which a nitrogenous base is present alongside a sugar (ribose or deoxyribose) and a phosphate group. Since cytidine does not have a phosphate group, it is not a nucleotide.

Nucleic acids: These are macromolecules containing nucleotides.