Núcleo (en. Core)

/ˈnu.kle.o/

Slang Meanings

In the academic field, it refers to the group of the most committed students.
That group is the core of the class, they are always participating.
Ese grupo es el núcleo de la clase, siempre está participando.
In the context of social groups, it refers to the closest friends.
My group of friends is always there to support me.
Mi núcleo de amigos siempre está ahí para apoyarme.