noun the number four; a collection of four things; a quaternion.
2. tetrad ·noun a tetravalent or quadrivalent atom or radical; as, carbon is a tetrad.
TETRAD
Meaning of TETRAD in English
Webster English vocab. Английский словарь Webster. 2012
noun the number four; a collection of four things; a quaternion.
2. tetrad ·noun a tetravalent or quadrivalent atom or radical; as, carbon is a tetrad.
Webster English vocab. Английский словарь Webster. 2012