- Sociology. a person, as a parent or peer, who has great influence on one's behavior and self-esteem.
- a spouse or cohabiting lover.
- US informal a spouse or lover
A person whose close relationship with an individual affects that individual's behavior and attitudes. A significant other is usually a family member, spouse, child, employer, coworker, friend, or lover, who serves as a role model or whose acceptance and approval is sought.