tetrahedral

[ te-truh-hee-druh l ]

/ ˌtɛ trəˈhi drəl /

pertaining to or having the form of a tetrahedron.

having four lateral planes in addition to the top and bottom.

Origin of tetrahedral

First recorded in 1785–95; tetrahedr(on) + -al¹

tet·ra·he·dral·ly, adverb

The young spores (G, H) are nearly colorless and are tetrahedral (like a three-sided pyramid) in form.

Elements of Structural and Systematic Botany |Douglas Houghton Campbell
Polar spines very thick and short, tetrahedral, one-fourth as long and broad as the major axis.

Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, First Part: Porulosa (Spumellaria and Acantharia) |Ernst Haeckel
To the south, 27 E., is a tetrahedral peak, which our guide called Ngoma-dingding.

Trans-Himalaya, Vol. 2 (of 2) |Sven Hedin
The tetrahedral or Reye complex is the simplest and best known of proper quadratic complexes.

Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 |Various

In Peripatus capensis the organ in question can hardly be described as tetrahedral.

The Works of Francis Maitland Balfour, Volume 1 |Francis Maitland Balfour