There are numerous synonymous expressions that can be used in place of the phrase "be a possibility." Some of these include "be a potentiality," "be a likelihood," "be an option," "be feasible," "be within the realm of possibility," "be on the cards," and "be in the cards." These phrases convey the idea that something is possible or could happen, but may not be a definite outcome. They can be used in a range of contexts, such as discussing potential outcomes of a situation or predicting future events. Choosing the right synonym depends on the tone and emphasis of the message being conveyed.