# nucleoside

> English word · Noun · IPA /ˈn(j)u(ː)kliəˌsaɪd/ · frequency rank #71,747

## Definitions
1. an organic molecule in which a nitrogenous heterocyclic base (or nucleobase), which can be either a double-ringed purine or a single-ringed pyrimidine, is covalently attached to a five-carbon pentose sugar (deoxyribose in DNA or ribose in RNA). When the phosphate group is covalently attached to the pentose sugar, it forms a nucleotide.

## Etymology
Probably from nucleo- + (glyc)oside.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/nucleoside