Callups refer to the process of summoning a person or persons to join an organization or team, especially for military service. The antonyms for callups include demobilization, discharge, dismissal, and release. Demobilization is the process of discharging members of the armed forces from military service. Discharge refers to the formal release of an individual from military service. Dismissal, on the other hand, refers to being fired or being legally removed from a job. Release refers to setting someone free from military duty, imprisonment, or custody. These words are opposite in meaning to callups, and they convey the sentiments of ending or rejecting an obligation to serve or remain in an organization.