Girl Wearing Superhero Panties

Most dictionary definitions and common usages of the term are generic and not limited to the characters of any particular company or companies.
Nevertheless, variations on the term "Super Hero" are jointly claimed by DC Comics and Marvel Comics as trademarks. Registrations of "Super Hero" marks have been maintained by DC and Marvel since the 1960s. (U.S. Trademark Serial Nos. 72243225 and 73222079, among others).
Joint trademarks shared by competitors are rare in the United States. They are supported by a non-precedential 2003 Trademark Trial and Appeal Board decision upholding the "Swiss Army" knife trademark. Like the "Super Hero" marks, the "Swiss Army" mark was jointly registered by competitors. It was upheld on the basis that the registrants jointly "represent a single source" of the knives, due to their long-standing cooperation for quality control.
Critics in the legal community dispute whether the "Super Hero" marks meet the legal standard for trademark protection in the United States-distinctive designation of a single source of a product or service. Controversy exists over each element of that standard: whether "Super Hero" is distinctive rather than generic, whether "Super Hero" designates a source of products or services, and whether DC and Marvel jointly represent a single source. Some critics further characterize the marks as a misuse of trademark law to chill competition.