Masochism

The English dictionary definition

1. (Psychiatry.) the condition in which sexual gratification depends on suffering, physical pain, and humiliation.
2. gratification gained from pain, deprivation, degradation, etc., inflicted or imposed on oneself, either as a result of one's own actions or the actions of others, esp. the tendency to seek this form of gratification.
3. the act of turning one's destructive tendencies inward or upon oneself.
4. the tendency to find pleasure in self-denial, submissiveness, etc.

It should be noted that many members of the BDSM community seek out pain principally since it enhances their sexual experience. However, for many masochists the pain/suffering/humiliation is a form of gratification within itself.

A common sexual perspective

Masochism is the counterpart to sadism, the sexual pleasure or gratification of having pain or suffering inflicted upon the self, often consisting of sexual fantasies or urges for being beaten, humiliated, bound, tortured, or otherwise made to suffer, either as an enhancement to or a substitute for sexual pleasure. The name is derived from the name of the 19th century author Leopold von Sacher-Masoch, known for his novel Venus in Furs that dealt with highly masochistic themes.

A masochist does not in general take pleasure in any arbitary form of pain, only in pain received under the pretext of enforcing authority, and typically only that of a sexual nature. Likewise, a sadist usually only takes pleasure in pain that is inflicted for reasons of punishment and control, and most often for the indirect pleasure of the masochist. Many sadomasochistic activities involve only mild pain or discomfort. Often they are focused primarily on roleplay.

The term BDSM has been created to describe the quite common activities between consenting adults that contain sadistic and masochistic elements. Many behaviors such as erotic spanking and love-bites that many people think of only as "rough" sex also contain elements of sado-masochism.