This is the 791st most frequent Spanish word.
álvarez
"Álvarez" is a Spanish surname meaning "son of Álvaro."
Here, 'Álvarez' is used as a part of a title to identify a specific person qualified as a doctor.
El doctor Álvarez llegará al hospital a las diez.
Doctor Álvarez will arrive at the hospital at ten.
In this example, 'Álvarez' refers to the name of a company that sponsors a sports team, indicating the usage of a proper noun in a corporate context.
El equipo de fútbol, patrocinado por Álvarez Hermanos S.A., ganó el campeonato.
The soccer team, sponsored by Álvarez Hermanos S.A., won the championship.
In this sentence, 'Álvarez' is used as a surname referring to a family's last name.