from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Of or relating to a tetrahedron.
- adj. Having four faces.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. in the shape of a tetrahedron
- adj. having four faces, four apices and six edges
from the GNU version of the Collaborative International Dictionary of English
- adj. Having, or composed of, four sides.
- adj. Having the form of the regular tetrahedron.
- adj. Pertaining or related to a tetrahedron, or to the system of hemihedral forms to which the tetrahedron belongs.
from The Century Dictionary and Cyclopedia
- Pertaining to a tetrahedron.
- In crystallography: Having the form of the regular tetrahedron.
- Pertaining or relating to a tetrahedron, or to the system of forms to which the tetrahedron belongs: as, tetrahedral hemihedrism (see hemihedrism).
The lugsails are arranged in a tetrahedral, that is, each of the four lugsails is oriented exactly 109.47 degrees from the other three.
"That's a different kind," the Forecaster answered, "it's called a tetrahedral kite, and was invented by Dr. Alexander Graham Bell.
The tetrahedral vessel would bounce and land on one of its faces, and one or the other of them would be right-side up and in a position to help the others.
Like a routine play nine hundred and ninety eight spindly human figures stepped forth onto the walls and filed towards the black emptiness arranged around the Core in what a chemist or mathematician might call tetrahedral bipyramidal form.
This stereochemical concept rests on the original suggestion by van't Hoff of the tetrahedral arrangement of the four valences of the carbon atom (see Section 2), and most organic molecules exist in two or more stable conformations.
German physicist Willhelm Conrad Röntgen, who discovered X-rays in the late 19th century, published a paper proposing that liquid water comprised two different structures — one tetrahedral “ice-like” structure, and another more loosely arranged structure, which helped explain why water behaves in such unusual ways.
Lowell Gilbert @ 13, kid bitzer @ 15 -- Remember that the tetrahedral shape is that of the four bonds of the carbon atom; the implied tetrahedra are connected tip-to-tip, not solidly packed.
In addition to using these skeletal tetrahedral frames as geological armatures, to hold back the earth and facilitate access, they will also bore through the bedrock, drilling new passages and eroding caverns to dwarf the nave of St. Peter's, wherein they will lock into place as columns, arches and internal buttresses.
He went to the tetrahedral capsule's backside, and twisted the knob that should have immediately opened the cover plate of the Mars Shelter Unit stowage compartment.
“Clay” as a mineral refers to a “cousin” of micas; that is, a silicate mineral containing structural sheets of silica tetrahedra tetrahedral arrangements of one Si and 4 Oxygen atoms, with the Oxygen atoms at the 4 corners.