codon

American

[koh-don] / ˈkoʊ dɒn /

noun

Genetics.

a triplet of adjacent nucleotides in the messenger RNA chain that codes for a specific amino acid in the synthesis of a protein molecule.

codon British

/ ˈkəʊdɒn /

noun

genetics biochem a unit that consists of three adjacent bases on a DNA molecule and that determines the position of a specific amino acid in a protein molecule during protein synthesis

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

codon Scientific

/ kō′dŏn′ /

A sequence of three adjacent nucleotides on a strand of a nucleic acid (such as DNA) that constitutes the genetic code for a specific amino acid that is to be added to a polypeptide chain during protein synthesis. Some amino acids are coded for by more than one codon, and some codons do not signal a particular amino acid but rather signal a stop to protein synthesis.

codon Cultural

A group of three bases on the DNA molecule. Each codon determines the identity of one amino acid in proteins made by the cell.

Etymology

Origin of codon

An Americanism dating back to 1960–65; code + -on ¹

Compare meaning

How does codon compare to similar and commonly confused words? Explore the most common comparisons:

codon vs. anticodon

Vocabulary lists containing codon

Genetics - Middle School

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Example Sentences

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Cells read genetic instructions in sets of three letters called codons, and each codon corresponds to a specific amino acid.

From Science Daily • Feb. 28, 2026

Even so, each codon has traditionally been understood to carry only one meaning.

From Science Daily • Feb. 28, 2026

In nearly all organisms studied so far, every three letter codon either specifies one particular amino acid or signals the end of a protein.

From Science Daily • Feb. 28, 2026

The relationship between a nucleotide codon and its corresponding amino acid is called the genetic code.

From Textbooks • Apr. 25, 2013

The initiator tRNA interacts with the AUG start codon, and links to a special form of the amino acid methionine that is typically removed from the polypeptide after translation is complete.

From Textbooks • Apr. 25, 2013

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023