This is the 195th most frequent Hebrew word.
אותנו
"Us" or "ourselves."
The word 'אותנו' is used here to indicate the group of people including the speaker, who are being directly addressed by the teacher.
המורה ביקשה מאיתנו להקשיב בשקט.
The teacher asked us to listen quietly.
'אותנו' functions as the object of the verb 'invited', referring to the group including the speaker.
החברים שלנו הזמינו אותנו למסיבה.
Our friends invited us to the party.
In this sentence, 'אותנו' serves as the direct object receiving the action performed by the guide.