triradius

American  

[trahy-rey-dee-uhs] / traɪˈreɪ di əs /

noun

Physical Anthropology.

PLURAL

triradii, triradiuses

1. a Y -shaped group of ridges on the palm of the hand at the base of each finger.

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Etymology

Origin of triradius

tri- + radius

Example Sentences

The normal angle is around 48�; the higher the axial triradius, the larger the angle�around 80� in mongolism, and still greater in some of the other chromosomal abnormalities.

From Time Magazine Archive

British researchers measure the angle between the axial triradius and those at the base of the index and little fingers.

From Time Magazine Archive

Then there are five places where the normal palm shows what researchers call a triradius�a wide-open letter Y formed by the junction of three lines.

From Time Magazine Archive

The crucial one is the axial triradius; on most palms it is just above the first flesh crease where hand joins wrist.

From Time Magazine Archive