Misogyny has many different practical meanings, but its most basic definition is a hatred of women. The term misogyny is used almost exclusively negatively, although it is arguable that an overt misogynist might use the term in a positive manner. Typically, misogynists are not people accused of hating women explicitly, but people who have betrayed a covert and deep hatred of women. Conceptually, misogyny has existed for as long as women have been conceived of as a group of people, although the term itself has Greek origins.
While misogyny is defined as a hatred of women, in practice it is used to refer to any case in which women face discrimination. When women are treated as less than men, accusations of misogyny abound. This is a somewhat stretched use of the term, as one need not necessarily hate a group of people in order to discriminate against them. In fact, indifference can be more of a gateway to discrimination than hatred. Misogyny, in a technical sense, is better used to describe cases where there is an emotional investment in the discrimination against women.
A more accurate portrayal of a misogynist might be someone who refuses to associate with women due to hatred or who assaults a female partner and looks down on all other women. These people are often covert about their emotions, but people like serial killers who act on an intense hatred of women could also be called misogynists. It is much more common to hear the term used for minor and insubstantial cases of woman hating rather than serious and actual cases of abuse of women.
It is important to note that misogynists do not hate particular women but women as a group. This is to say that while any person might hate a single woman, a misogynist hates women as a group simply for being women. That hatred may be rooted in distaste for a single woman, but the misogynist experiences hatred for the entire group.
Misogyny is not limited to men, and in fact is not limited to single people at all. An entire society can be said to be misogynist, although the term is often used to refer to subtle undercurrents of discrimination. Religions, philosophies, and cultures are all often said to be misogynist. In essence, any person, group, or thing that calls into question the sameness of women and men can appropriately be called misogynist by any person willing to argue that the term is appropriate in that case. As a word that is frequently overused and misused, the term misogyny is frequently employed as no more than a way to shame one's opponent in an argument by unfairly accusing him or her of bigotry.