exon

noun

ex·​on ˈek-ˌsän 

: a polynucleotide sequence in a nucleic acid that codes information for protein synthesis and that is copied and spliced together with other such sequences to form messenger RNA compare intron

exonic

ek-ˈsä-nik 

adjective

Examples of exon in a Sentence

Recent Examples on the Web

Entrada is one of a group of companies developing new exon-skipping drugs. — Jason Mast, STAT, 7 May 2026

In the same way, a cell can join different exons together to form distinct versions of a protein, known as isoforms, each with its own shape and function. — William A. Haseltine, Forbes.com, 7 Apr. 2026

These molecules were engineered to boost poison exon activity in TRA2β, restoring the gene's self-regulating mechanism. — Jenny Lehmann, Discover Magazine, 18 Mar. 2025

Most of the time, cells connect exons from the same pre-RNA molecule to make the mRNA. — Bymitch Leslie, science.org, 24 Oct. 2024

Word History

Etymology

expressed sequence + -on entry 2

First Known Use

circa 1978, in the meaning defined above

Rhymes for exon

• anton
• argon
• axon
• baronne
• baryon
• baton
• boron
• buisson
• bygone
• capon
• cardon
• chiffon

Medical Definition

exon

noun

ex·​on ˈek-ˌsän 

: a polynucleotide sequence in a nucleic acid that codes information for protein synthesis and that is copied and spliced together with other such sequences to form messenger RNA compare intron

exonic

ek-ˈsän-ik 

adjective