This is the 549th most frequent Spanish word.
familiar
"Familiar" in Spanish means "related to family" or "well-known."
The word 'familiar' is used as an adjective to describe something that pertains to or is characteristic of a family.
Ella tiene un ambiente familiar en su casa.
She has a family-like environment in her house.
Here, 'familiar' functions as an adjective meaning well-acquainted or knowledgeable about something.
Él es un amigo muy familiar con nuestras costumbres.
He is a friend very familiar with our customs.
In this case, 'familiares' is a plural adjective referring to things belonging to or related to the family.