A bromance is a very close and non-sexual relationship between two or more men. It is an exceptionally tight, affectional, homosocial male bonding relationship exceeding that of usual friendship, and is distinguished from normal friendship by a particularly high level of emotional intimacy. The emergence of the concept since the beginning of the 21st century has been seen as reflecting a change in societal perception and interest in the theme, with an increasing openness of Western society in the 21st century to reconsider exclusivity constraints. The female versione of the bromance is the womance.

Bro culture is a subculture of young people who spend time partying with others like themselves. Although the original image of the bro lifestyle is associated with sports apparel and fraternities, it lacks a consistent definition. Most aspects vary regionally, such as in California, where it overlaps with surf culture. Oxford Dictionaries have noted that bros frequently self-identify with neologisms containing the word "bro" as a prefix or suffix.