noun
Etymology: Middle English ful age, full age
: mature age or legal majority ; specifically : the time of life at which one attains full personal rights and capacities, which under common law is attained upon the last day of completing 21 years or specifically on the first instant of the day preceding the 21st birthday and under civil law is attained upon completing 25 years, and which in some states is attained by women upon completing 18 years