For those wanting to know what the new Snapchat emoji symbols mean, there is several different things that they repersent and these emojis have replaced the âBest Friendsâ feature with Friend Emojis smilies.
(plural tetrads) 1  A group of four things. ( 2 chemistry) A tetravalent atom or radical. ( biology) Two pairs of sister chromatids (a dyad pair) aligned in a certain way and often on the equatorial plane during the meiosis process.
Updated November 18, 2014. Definition: Tetrahedral is a descriptor of the geometry of a molecule in which a central atom forms four bonds which are directed toward the corners of a regular tetrahedron. Tetrahedral geometry forms a solid with four vertices and four sides, all of which are equilateral triangles.