double helix

noun

: a helix or spiral consisting of two strands in the surface of a cylinder that coil around its axis
especially : the structural arrangement of DNA in space that consists of paired polynucleotide strands stabilized by cross-links between purine and pyrimidine bases compare alpha-helix, watson-crick model
double-helical
ˌdə-bəl-ˈhe-li-kəl How to pronounce double helix (audio)
-ˈhē-
adjective

Examples of double helix in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
There’s a double helix in my local Sephora. — Will Gottsegen, The Atlantic, 23 Jan. 2026 The double helix fragments, and bases change identity or fall off entirely. — ArsTechnica, 13 May 2026 The track is packed with thrills, featuring three 360-degree spirals, an 80-foot double helix, two uphill stretches, and a mid-race bridge that offers the perfect chance to size up your opponent and take in the views. — Jacqueline Dole, Travel + Leisure, 18 Sep. 2025 Adenine, guanine, cytosine, and thymine are the four bases of the genetic code that make up the rungs of the double helix structure of DNA by forming specific pairs (adenine pairs with thymine, guanine with cytosine). — Robert Lea, Space.com, 17 Mar. 2026 See All Example Sentences for double helix

Word History

First Known Use

1954, in the meaning defined above

Time Traveler
The first known use of double helix was in 1954

Rhymes for double helix

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Browse Nearby Words

doublehearted
double helix
double house
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Cite this Entry

“Double helix.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/double%20helix. Accessed 8 Jul. 2026.

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Kids Definition

double helix

noun
: the arrangement in space of DNA that resembles a spirally twisted ladder with the sides made up of the sugar and phosphate units of the two nucleotide strands and the rungs made up of the pyrimidine and purine bases extending into the center and joined by hydrogen bonds

Medical Definition

double helix

noun
: a helix or spiral consisting of two strands in the surface of a cylinder that coil around its axis
especially : the structural arrangement of DNA in space that consists of paired polynucleotide strands stabilized by cross-links between purine and pyrimidine bases compare alpha-helix, watson-crick model
double-helical
-ˈhel-i-kəl How to pronounce double helix (audio) -ˈhē-li- How to pronounce double helix (audio)
adjective

More from Merriam-Webster on double helix

Britannica.com: Encyclopedia article about double helix

Last Updated: - Updated example sentences
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