Share this entry

helix Line breaks: helix
Pronunciation: /ˈhiːlɪks/

Definition of helix in English:

noun (plural helices ˈhiːlɪsiːzˈhɛlɪsiːz)

Image of helix
1An object having a three-dimensional shape like that of a wire wound uniformly in a single layer around a cylinder or cone, as in a corkscrew or spiral staircase.
Example sentences
  • They found that DNA consists of two connected twisted strands in the shape of a helix.
  • The excess is carefully cut away to fabricate the helix shape.
  • A television monitor showed what was inside: a glowing ball of gas surrounded by a metal helix.
spiral, coil, curl, corkscrew, twist, twirl, loop, gyre, whorl, scroll, curlicue, convolution
technical volute, volution
1.1 Geometry A curve on a conical or cylindrical surface which would become a straight line if the surface were unrolled into a plane.
Example sentences
  • A template in the shape of a narrow right-angle triangle is wrapped around the cylinder to be threaded, and the hypotenuse of the triangle forms the line of the helix.
  • The conical helix of their upward spiral against the flat blue sky is completely hypnotic.
1.2 Biochemistry An extended spiral chain of atoms in a protein, nucleic acid, or other polymeric molecule.
Example sentences
  • The gray bands indicate the helix regions of the protein.
  • DNA molecules in nature are built from two complementary strands that bind to form the double helix.
  • The double helix of DNA is held together by hydrogen bonds.
1.3 Architecture A spiral ornament.
Example sentences
  • Ross Lovegrove's stairway, with its helix profile, is part of a new tendency by designers to borrow forms from nature.
2 Anatomy The rim of the external ear.
Example sentences
  • The ear print on the safe had a circular mark at the top of the ear helix.
  • Decrease oxygen saturation in blood in the helix of the ear by using an ear oximeter.


Mid 16th century (in the architectural sense 'spiral ornament'): via Latin from Greek.

Words that rhyme with helix


Definition of helix in:

Share this entry


What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.

Get more from Oxford Dictionaries

Subscribe to remove adverts and access premium resources

Word of the day fortissimo
Pronunciation: fɔːˈtɪsɪməʊ
(especially as a direction) very loud or loudly