Roster/ˈrɑːstər/ Definition 1 of 2Pro Tip 1/3Group Membership Use 'roster' to show who belongs to a team or group at a particular time. Our club's roster has been updated for the spring semester. Pro Tip 2/3Selection and Roles 'Roster' can indicate not only who is in a group but also their specific roles or tasks. The event roster lists Sarah as the main speaker. Pro Tip 3/3Organizational Tool Organizations use a roster to track members, making it a key administrative tool. Please check the roster to confirm your membership status.