late 14c., "play or other serious literary work with an unhappy ending," from Old French tragedie (14c.), from Latin tragedia "a tragedy," from Greek tragodia "a dramatic poem or play in formal language and having an unhappy resolution," apparently literally "goat song," from tragos "goat, buck" + ōidē "song" (see ode), probably on model of rhapsodos (see rhapsody).
The connection may be via satyric drama, from which tragedy later developed, in which actors or singers were dressed in goatskins to represent satyrs. But many other theories have been made (including "singer who competes for a goat as a prize"), and even the "goat" connection is at times questioned. Meaning "any unhappy event, disaster" is from c. 1500.
early 15c., "full of misery, causing wretchedness" (of conditions), from Old French miserable (14c.) and directly from Latin miserabilis "pitiable, miserable, deplorable, lamentable," from miserari "to pity, lament, deplore," from miser "wretched" (see miser). Of persons, "existing in a state of want, suffering, wretchedness, etc.," it is attested from 1520s. Meaning "mentally full of misery, wretched in feeling unhappy," by 1590s. Related: Miserableness.
The sense associated with miser, "covetous, miserly," is attested from late 15c., but by 1895 (Century Dictionary) was "obsolete or Scotch." As a noun, "an unfortunate, an unhappy creature," 1530s (reinforced later by the French cognate, as in Hugo's "Les Misérables").