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

The defense team plans to employ Othram to conduct a Y-STR test, a method that isolates DNA from the Y chromosome to generate a profile of a male contributor in samples where female DNA is predominant. — Adam Sabes, FOXNews.com, 17 Oct. 2026

The body normally keeps LINE1 quiet through DNA methylation, chemical tags that silence the sequence. — Hanna Wickes, Charlotte Observer, 17 Oct. 2026

Related Stories Betu Martínez Molero, Serielizados’ co-founder with Victor Sala, unpacks the festival’s DNA and program highlights. — Annika Pham, Variety, 16 Oct. 2026

The defense said in a court filing that DNA testing confirmed Farwell was not the father. — Kristina Rex, CBS News, 16 Oct. 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