To call through means to make a phone call or attempt to contact someone by phone, especially when they are not readily available or when there is a need for urgent communication. This term is often used in professional settings, such as in business or customer service, to indicate the act of reaching out to someone via phone in order to discuss important matters or provide updates. It can also refer to the process of making multiple attempts to reach someone if they do not answer the initial call. Overall, calling through is a way to efficiently and effectively communicate with someone when traditional methods may not be feasible.