Labeling means applying a name to a phenomenon or a pattern of behavior. The label may acquire negative connotations or be applied erroneously to the person rather than that person’s behaviors.
Other definition:
Labeling refers to a social process in which an individual is designated as having a certain disease or disorder; once given this label, the individual acts in ways that conform to the label. It means putting extreme "titles" on people or situations Labeling may also be defined as: application of a name to a phenomenon or a pattern of behavior. The label may acquire negative connotations or be applied erroneously to the person rather than that person’s behaviors; and creation of a negative view of oneself based on errors or mistakes that one has made. It is a type of overgeneralizing which affects one’s view of oneself.
Other definition:
Labeling refers to an interactionist perspective which sees continued crime as a consequence of limited opportunities for acceptable behavior which follow from the negative responses of society to those defined as offenders.