Vanessa The definition of it is:
masochism (countable and uncountable, plural masochisms)
The enjoyment of receiving pain or humiliation.
According to ICD-10, sadomasochism is considered a "disorder of sexual preference" (key F65.5), which is described there as follows:
Sexual activities involving the infliction of pain, humiliation, or bondage are preferred. If the affected person suffers this type of stimulation, it is masochism; if they inflict it on someone else, it is sadism. Often the affected person experiences sexual arousal during both masochistic and sadistic activities.