The phrase "to single out" means to select or choose one person, thing, or group from among others. It can also mean to identify someone as different or unique in some way, often in a negative context. For example, if a teacher singles out a student for praise, it is seen as positive; however, if an employer singles out an employee for criticism, it may be viewed negatively. The phrase can also refer to highlighting something as distinct from other things or focusing on one aspect while ignoring others.