Significant other is a gender-blind, politically correct term to refer to a personís partner in a romantic relationship without disclosing his or her personal or lifestyle choices or sexual orientation.
The first known occurrence of the term was in 1953 by U.S. psychiatrist, Harry Stack Sullivan, a former editor of the journal Psychiatry, in his work, The Interpersonal Theory of Psychiatry.
Its usage in both psychology and sociology is much different than its more common use. In psychology, a significant other is any person who has great importance to an individualís life or well-being. In sociology, it describes a person with a strong influence on an individual's self-evaluation as well as reception of particular social norms. This usage is synonymous with the term "relevant other."