from The American Heritage® Dictionary of the English Language, 4th Edition

  • adj. Concave on both sides or surfaces: a biconcave lens.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • adj. Having both sides concave.

from the GNU version of the Collaborative International Dictionary of English

  • adj. Concave on both sides.

from The Century Dictionary and Cyclopedia

  • Hollow or concave on both sides; doubly concave, as a lens. See lens.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adj. concave on both sides


Sorry, no etymologies found.


  • Real red blood cells owe their astonishing agility to their "biconcave" or tyre-like shape, and to get the same kind of synthetic particles, Samir Mitragotri and his team got their inspiration from the way real red blood cells acquire their final shape in the body.

    Gaea Times (by Simple Thoughts) Breaking News and incisive views 24/7

  • Real red blood cells owe their astonishing agility to their "biconcave" or tyre-like shape.

    Fight Aging!

  • Again, the more ancient Crocodilia and Lacertilia have vertebrae with the articular facets of their centra flattened or biconcave, while the modern members of the same group have them procoelous.


  • ‘Polypterus’, and presenting numerous important resemblances to the existing genus, which possesses biconcave vertebrae, are, for the most part, wholly devoid of ossified vertebral centra.


  • (Gr. [Greek: koilae], a hollow) or _angulus lunularis_, biconcave.

    Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1

  • The human blood-corpuscle is a non-nucleated, biconcave disc, having a diameter of about 1/3500 of an inch.

    Aids to Forensic Medicine and Toxicology

  • Colored or red corpuscles (erythrocytes), when examined under the microscope, are seen to be circular disks, biconcave in profile.

    V. Angiology. 2. The Blood

  • The disk has no nucleus, but, in consequence of its biconcave shape, presents, according to the alterations of focus under an ordinary high power, a central part, sometimes bright, sometimes dark, which has the appearance of a nucleus (Fig. 453, a).

    V. Angiology. 2. The Blood

  • In reality, as everybody knows nowadays, these are biconcave disks, but owing to their peculiar figure it is easily possible to misinterpret the appearances they present when seen through a poor lens, and though Dr. Thomas Young and various other observers had come very near the truth regarding them, unanimity of opinion was possible only after the verdict of the perfected microscope was given.

    A History of Science: in Five Volumes. Volume IV: Modern Development of the Chemical and Biological Sciences

  • They retained the evidence of their close relationship with the Devonian fishes in their cold blood, their gills and aquatic habit during their larval stage, their teeth with dentine infolded like those of the Devonian ganoids but still more intricately, and their biconcave vertebrae which never completely ossified.

    The Elements of Geology


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