requiring effort or concentration; complex and not easy to answer or solve; "raised serious objections to the proposal"; "the plan has a serious flaw"
of great consequence; "marriage is a serious matter"
concerned with work or important matters rather than play or trivialities; "a serious student of history"; "a serious attempt to learn to ski"; "gave me a serious look"; "a serious young man"; "are you serious or joking?"; "Don't be so serious!"
any natural satellite of a planet; "Jupiter has sixteen moons"
the natural satellite of the Earth; "the average distance to the moon is 384,400 kilometers"; "men first stepped on the moon in 1969"
any object resembling a moon; "he made a moon lamp that he used as a night light"; "the clock had a moon that showed various phases"
United States religious leader (born in Korea) who founded the Unification Church in 1954; was found guilty of conspiracy to evade taxes (born in 1920)