This is the 8004th most frequent Spanish word.
mr
The term "mr" is not a Spanish word.
The word 'señor' here means 'Mr.', used as a formal title for addressing a man by his last name.
El señor González es mi profesor de matemáticas.
Mr. González is my mathematics teacher.
In this sentence, 'señores' means 'gentlemen', used as a respectful plural form to address a group of men.
Señores, por favor pasen a la sala de reunión.
Gentlemen, please proceed to the meeting room.
Although not explicitly 'Mr.', this usage demonstrates the counterpart 'señorita', meaning 'Miss' to respectfully address a woman by her last name.