Definition of helix in English:



  • 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.

    • ‘He was looking at the picture of the helix.’
    • ‘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.’
    • ‘Although Concrete art is typically austerely geometrical, it is not necessarily so; Bill's sculpture, for example, often uses graceful spiral or helix shapes.’
    • ‘Terrified, he ran to a stairwell; its helix curved upward toward the floors above.’
    • ‘The fibers themselves are assumed to be straight helices.’
    • ‘Both had almost the same number of helices, strands and turns.’
    • ‘The crucial trick is that the helix is not even: it has a significantly larger diameter in the middle than at the ends.’
    • ‘It described his proposal for a different type of helical structure, which he called the helix.’
    • ‘Seven of the predicted helices in our final structure are consistent with the model of MacDonald.’
    • ‘The building blocks are chosen so that the ribbon curls into a helix.’
    spiral, coil, curl, corkscrew, twist, twirl, loop, gyre, whorl, scroll, curlicue, convolution
    volute, volution
    View synonyms
    1. 1.1Geometry A curve on a conical or cylindrical surface which would become a straight line if the surface were unrolled into a plane.
      • ‘The conical helix of their upward spiral against the flat blue sky is completely hypnotic.’
      • ‘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.’
    2. 1.2Biochemistry An extended spiral chain of atoms in a protein, nucleic acid, or other polymeric molecule.
      • ‘It turns out that a helix, essentially, is a great way to bunch up a very long molecule, such as DNA, in a crowded place, such as a cell.’
      • ‘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.’
      • ‘The gray bands indicate the helix regions of the protein.’
      • ‘Part of the gene was not arranged in the double helix structure, they noticed.’
    3. 1.3Architecture A spiral ornament.
      • ‘Ross Lovegrove's stairway, with its helix profile, is part of a new tendency by designers to borrow forms from nature.’
  • 2Anatomy
    The rim of the external ear.

    • ‘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.