Merriam-Webster Logo
SINCE 1828
Menu
×

double helix

noun
|Updated on: 8 Jun 2018

Definition of double helix

: 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

play \-ˈhe-li-kəl, -ˈhē-\ adjective

See double helix defined for English-language learners

See double helix defined for kids

Recent Examples of double helix from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'double helix.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of double helix

1954

in the meaning defined above

See Words from the same year
NEW! Time Traveler

DOUBLE HELIX Defined for English Language Learners

double helix

noun

Definition of double helix for English Language Learners

  • : the shape formed by two parallel lines that twist around each other

Medical Dictionary

double helix

noun

medical Definition of double helix

: 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

play \-ˈhel-i-kəl, -ˈhē-li-\ adjective

Illustration of double helix

illustration of double helix

Learn More about double helix

  1. Britannica.com: Encyclopedia article about double helix

Seen and Heard

What made you want to look up double helix? Please tell us where you read or heard it (including the quote, if possible).

show hide

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

notorious

play

widely and unfavorably known

Get Word of the Day daily email!

TRENDING NOW

  1. asylum 'protection from arrest and extradition given especially to political refugees'

  2. insubordinate 'disobedient to authority'

  3. promulgate 'to make known by open declaration'

  4. epochal 'momentous or unparalleled'

  5. clemency 'merciful treatment of someone who could be given harsh punishment'

SEE ALL

BROWSE DICTIONARY

double helix

Test Your Vocabulary

Words for Summer: A Quiz

  • a-closeup-of-a-sunflower
  • Which of the following words means “of or relating to summer”?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words at Play

Ask the Editors

Word Games