DNA

noun

ˌdē-ˌen-ˈā 

: any of various nucleic acids that are usually the molecular basis of heredity, are constructed of a double helix held together by hydrogen bonds between purine and pyrimidine bases (see base entry 1 sense 6b) which project inward from two chains containing alternate links of deoxyribose and phosphate, and that in eukaryotes are localized chiefly in cell nuclei compare recombinant dna

Illustration of DNA

• A molecular model
• 1 hydrogen
• 2 oxygen
• 3 carbon in the helical phosphate ester chains
• 4 carbon and nitrogen in the cross-linked purine and pyrimidine bases
• 5 phosphorus
• B double helix

Examples of DNA in a Sentence

Recent Examples on the Web

Most consumer clocks are built on DNA methylation, a process in which chemical tags called methyl groups attach to DNA as a person ages, altering the cytosine base and creating a pattern that correlates with biological age. — Hanna Wickes, Miami Herald, 14 Sep. 2026

How the tests actually work Most biological aging clocks rely on a process called DNA methylation. — Hanna Wickes, Kansas City Star, 14 Sep. 2026

During the event, each designer showed five looks that best showed off their brand’s DNA. — Stephen Garner, Footwear News, 13 Sep. 2026

Boston said the charges followed years of investigative work from the DeKalb Cold Case Task Force, using advanced technology in DNA and genealogy mapping in cold cases. — Taylor Croft, AJC.com, 11 Sep. 2026

Word History

Etymology

deoxyribonucleic acid

First Known Use

1944, in the meaning defined above

Phrases Containing DNA

• DNA fingerprinting
• DNA methylation
• DNA phenotyping
• DNA polymerase
• DNA test
• DNA virus
• junk DNA
• mitochondrial DNA
• recombinant DNA
• satellite DNA

Rhymes for DNA

• ay
• bay
• bey
• brae
• cay
• chez
• dey
• dray
• fay
• fey
• flay
• fray

Kids Definition

DNA

noun

ˌdē-ˌen-ˈā 

: any of various nucleic acids that are located especially in cell nuclei, are usually the chemical basis of heredity, and are composed of two nucleotide chains held together by hydrogen bonds in a pattern resembling a flexible twisted ladder compare rna

Medical Definition

DNA

noun

ˌdē-ˌen-ˈā 

: any of various nucleic acids that are usually the molecular basis of heredity, are constructed of a double helix held together by hydrogen bonds between purine and pyrimidine bases which project inward from two chains containing alternate links of deoxyribose and phosphate, and that in eukaryotes are localized chiefly in cell nuclei

called also deoxyribonucleic acid

see recombinant dna