Tetrad

Definition:

• (n.) The number four; a collection of four things; a quaternion.
• (n.) A tetravalent or quadrivalent atom or radical; as, carbon is a tetrad.

Compare tetrad with other words:

polyad vs. tetrad

tapetum vs. tetrad

tetrad vs. tetradic

radical vs. tetrad

atom vs. tetrad

tetrad vs. tetravalent

quadriad vs. tetrad