A black person.
A difficult, abstract problem that worsens as one attempts to handle it; a "sticky" situation, especially one where attempts to make it better only make it worse.
Any dark-skinned person: originally specifically an Indian, but later also anybody of North African, Mediterranean, or Middle Eastern ancestry.
A bug, an insect.
A person of Southern European, Mediterranean, Middle Eastern, or Southeastern European ancestry.
A pollywog, or sailor who has never crossed the Equator.
A minor illness caused by bacteria, virus, intestinal parasite, etc.
A person who is not a Scientologist.