Real Dictionary

tragedy
variable noun: A tragedy is an extremely sad event or situation.
variable noun: Tragedy is a type of literature, especially drama, that is serious and sad, and often ends with the death of the main character.

tragedy in American English
a serious play or drama typically dealing with the problems of a central character, leading to an unhappy or disastrous ending brought on, as in ancient drama, by fate and a tragic flaw in this character, or, in modern drama, usually by moral weakness, ps
noun: a dramatic composition, often in verse, dealing with a serious or somber theme, typically that of a great person destined through a flaw of character or conflict with some overpowering force, as fate or society, to downfall or destruction

tragedy in British English
noun: (esp in classical and Renaissance drama) a play in which the protagonist, usually a person of importance and outstanding personal qualities, falls to disaster through the combination of a personal failing and circumstances with which he or she cannot deal