This is the 4364th most frequent Spanish word.
stewart
"Stewart" is not a Spanish word.
In this sentence, 'Stewart' is used as a proper noun to refer to a person's name.
El nombre de mi amigo es Stewart.
My friend's name is Stewart.
Here, 'Stewart' acts as a surname, identifying a family name.
El apellido de esa familia es Stewart.
The last name of that family is Stewart.
Again, 'Stewart' serves as a proper noun for someone's personal name, highlighting their action.