Sexual harassment is behaviour of a sexual nature that is unsolicited, unwelcome and unreciprocated.
Most sexual harassment is by men against women. Probably less than a tenth is same-sex harassment and an even tinier fraction is by women against men. Sexual harassment has been pervasive for centuries. It is only in the past couple of decades, due to second-wave feminism in industrialised countries, that sexual harassment has been named and opposed in a systematic fashion. There is an obvious connection between nonviolent action and opposing sexual harassment.