An intensely emotional love relationship between two unrelated people, in which sexuality is unimportant and typically absent, but there is greater physical affection or poetic communication than is typical for friendship.
Faderman, Lillian, Surpassing the Love of Men: Romantic Friendship and Love Between Women From the Renaissance to the Present, ISBN0-688-13330-4 (Title and frequently throughout)
Coontz, Stephanie, The Way We Never Were: American Families and the Nostalgia Trap, ISBN0-465-09097-4, p. 66, 195
Rotundo, Anthony, "Romantic Friendship: Male Intimacy and Middle-Class Youth in the Northern United States, 1800-1900," Journal of Social History 23 (1989) : 20
The term was in common use from the Renaissance to the late 19th century and in modern times its use withered along with the concept to which it referred, but in addition to its use in social history, it is used by radical queer authors and in the asexual movement, where the modern notion of friendship as a less-intense relationship is sometimes challenged.