Maisie is a diminutive of Mairead, ultimately derived from Margaret. Margaret originates in Greek language and means "pearl". It is derived from the Greek word margarites. One of the most famous bearers of this name is probably the former Conservative Prime Minister of the UK Margaret Thatcher, nicknamed the "Iron Lady". The name has become popular again recently after decrease in usage within the 20th century and currently is one of the most popular feminine given names in the United States.