Definition of anhedral in US English:



  • (of a crystal) having no plane faces.

    • ‘The samarskite occurs as black to brown, metamict, anhedral, radiating aggregates to 30 cm in diameter.’
    • ‘Fluorite is found as purple or green crystals to 5 mm on edge and as anhedral masses in magnetite/hematite.’
    • ‘As seen in the granite, subhedral to anhedral grains of fayalite are fractured and show varying stages of alteration to hematite, antigorite, calcite, and magnetite.’
    • ‘Large anhedral masses of yttrian fluorite, measuring to several feet across, were found at the White Cloud pegmatite.’
    • ‘Petalite, LiAl [Si.sub.4] [O.sub.10], is found as lustrous whitish, anhedral masses that can reach many pounds and can be as much as 1 foot long.’
    • ‘Quartz occurs as anhedral grains with irregular, sutured grain boundaries; subgrain development is common and neoblasts may be evident in more deformed bodies.’
    • ‘The country granite typically has about 1/8 to 1/4 inch sized anhedral crystals of feldspar and quartz.’
    • ‘Monazite GS - 8-2, a sub - to anhedral grain, is c.70 m × 100 m, located between two apatite grains.’
    • ‘Most zircons are sharp-faceted, euhedral and elongate prisms, and minor amounts are transparent, pale brown, anhedral and rounded crystals.’
    • ‘Quartz is abundant, forming mainly subhedral to anhedral crystals up to about 1 mm in diameter that poikilitically enclose other crystals.’
    • ‘The generally submicron size and anhedral shape of microdolomite blebs appears to have been dictated by available spaces formed through micro-dissolution.’
    • ‘Subhedral to anhedral crystals of olivine (Fo83-73) occur as cumulus crystals which locally exhibit a crescumulitic texture.’
    • ‘Here, olivine (peridot when gemmy) grains or anhedral crystals weather out of basaltic lava.’
    • ‘It occurs in millimeter-sized anhedral grains or as bronze-colored hairlike crystals intimately intergrown with the oxide minerals.’
    • ‘A second textural type of titanite forms anhedral grains with plagioclase and pargasite, which is developed where the retrograde amphibolite-facies assemblage overprints the eclogite mineralogy.’
    • ‘Disintegration of the olivine-rich xenoliths probably accounts for much of the peridot found here, although many of the larger olivine grains occur as isolated anhedral grains embedded in the basalt.’
    • ‘The older crystals have anhedral zoning and irregular, corroded outlines.’
    • ‘Microcline is a common constituent of the intermediate zone, occurring as anhedral crystals to 60 cm.’
    • ‘In samples consisting mainly of feldspars, clinopyroxene, garnet or amphibole occur as sub - to anhedral grains and grain sixes become smaller.’
    • ‘The pyroxenoid occurs as granular masses of small anhedral crystals associated with manganoan magnetite.’


  • Downward inclination of an aircraft's wing.

    Compare with dihedral
    • ‘Some gliders have large amounts of anhedral to improve their handling and with this power steering addition the amount of anhedral may be reduced, making the glider more stable to fly and not requiring constant control inputs.’
    • ‘The AV-8B Harrier 'jump jet' is an example of a modern plane with anhedral wings.’
    • ‘High performance flex wings have to have anhedral in their wings in order to somewhat overcome their ‘stiffness’ in the initiation of a turn.’
    • ‘Competition flex wing hang gliders would be hard to turn if they didn't have a good amount of anhedral, as they don't have enough sail billow to allow weight shifting to change to shape of the sail quickly and easily.’
    • ‘Flex wings must rely on that pendulum under the wing and a certain amount of anhedral to overcome the fact that the sail just barely shifts (wing warping) on these high performance topless gliders.’
    • ‘I've found that hang gliders exhibit a negative coupling between yaw and roll - for example a right yaw will create a left roll - presumably due to anhedral.’
    • ‘The five-bladed main rotor is fully composite, with a composite spar, multiple box structure and anhedral tipcaps.’
    • ‘But adding anhedral makes for an unstable hang glider that is harder to keep straight.’
    • ‘Some gliders have far more anhedral than the Blade and the other gliders I tested and so the negative coupling effect would likely be even more pronounced on these wings.’
    • ‘The opposite of dihedral is called anhedral, and, of course, refers to a wing that is angled down.’
    • ‘I found the U2 to be light in roll and very responsive, without that twitchy feeling that sometimes comes from gliders with too much anhedral.’
    • ‘That many birds glide with some destabilizing anhedral (wings drooping slightly) suggests that the other stabilizing mechanisms available to them are more than adequate.’


Late 19th century (as an adjective): from an- ‘not’ + -hedral (see -hedron).