This appears to be a portmanteau or a misspelling of "nymphomaniac" (hypersexuality). In the context of the viral trend, it is often used colloquially (and sometimes inaccurately) to describe a person’s past lifestyle or a phase of intense dating and sexual activity.

If you are referring to this fictional character, she was involved in a legal and personal drama within the episode's plot.

Sydney Harwin's sister has been open about her struggles with addiction, revealing that she had been battling with substance abuse for years. Her journey to recovery began when she hit rock bottom and realized that she needed help. With the support of her family, including Sydney Harwin, she checked into a rehabilitation center and began her journey towards sobriety.