"Shut out" is a phrase that refers to the act of preventing someone or something from entering a particular place. This phrase can also be used in a metaphorical sense to describe the act of excluding someone from a social situation or conversation. To convey the same meaning, there are several synonyms one can use such as "exclude," "bar," "block," "ban," "prevent," "debar," "shut off," "shut away," "sequester," and "ostracize." Each of these words can be used in different contexts and have slightly different connotations, but they all imply the same sense of keeping someone or something out.