What is the definition or description of: sex addiction?

See below: Sexual addiction (sometimes called sex addiction) is a conceptual model divised in order to provide a scientific explanation for sexual urges, behaviors, or thoughts that appear extreme in frequency or feel out of one's control—in terms of being a literal addiction to sexual activity. This phenomenon is not newly described in the literature, but it has been described by many different terms.

Sex Addiction: Sexual urges, behaviors or thoughts that appear extreme in frequency or feel out of one's control. There's a pattern of recurrent failure to resist impulses to engage in acts of sex, persistent desire or unsuccessful effort to stop or control those behaviors, & continuation of the behavior despite knowledge of having social, academic, financial, psychological or physical problems caused by the beh.