tetrad

• Существительное, обозначающее число четыре или группу из четырёх предметов.

A noun referring to the number four, or a group or set of four things.

1. Group of fourC1formal

   A set or collection of four things, people, or elements.

   Четвёрка

   • The four musicians formed a tetrad for the performance.
   • In biology, a tetrad refers to a group of four cells.
   • The tetrad of seasons includes spring, summer, autumn, and winter.

   Synonymsfoursomequadquadrumviratequadruplequartet

2. Number fourC1formal

   The cardinal number that is the sum of three and one.

   Число четыре

   • The tetrad is often considered a symbol of stability.
   • In many cultures, the tetrad represents completeness.
   • The number four, or tetrad, appears frequently in ancient texts.

   Synonymsfourfoursomequadrupletquartetquaternionquaternity