The word epic comes from the Ancient Greek ‘epikós’, which means “word” or “story”. These stories described great heroes that undertook great adventures or participated in great wars. Some of these epics include Beowulf, The Odyssey, The Illiad, etc.
As the epic described great things, eventually the word also took on the meaning of great. Today, the word ‘epic’ describes something that is related to an epic poem, or something is great or momentous in nature. Anything that is considered extraordinary can be described as epic.
Today, epic is used as slang, as kids used epic to describe anything that is even slightly out of the ordinary. For example: an epic party, or an epic new game. Epic can also be used to describe something that is negative, such as epic fail.