Toxic masculinity is a term which became prevalent in the late 1980s and early 1990s. The original meaning was a hypermasculine stereotype: stoic, workaholic, macho, aggressive, unapologetic, and rugged. As used at first, toxic masculinity criticized the suggestion that those were the qualities of a "real man." It was not meant to suggest that everything male is inherently bad. Rather, those using the term were attempting to defend less caricatured expectations for men.
From Compelling Truth