An epitome (Greek epitemnein, to cut short) is a summary or miniature form; it is also used as a synonym for embodiment.

Many lost documents from the Ancient Greek and Roman world survive only now 'in epitome' referring to the practice of some later authors (epitomators) who would write distilled versions of now lost larger works. Some writers would attempt to convey the stance and spirit of the original, while others would add further details or anecdotes regarding the general subject. As with all secondary historical sources, a different bias may creep in that was not present in the original.

Documents surviving in epitome differ from those that survive only as fragments quoted in later works and those which were used as unacknowledged sources by later scholars, as they can stand as discrete documents, albeit ones that are refracted through the views of another author.

Examples of epitomes providing the only record of now lost works include:

• John Xiphilinus' precis of the missing portions of Cassius Dio's History of Rome.
• Justin's abridged version of the Philippic History by Gnaeus Pompeius Trogus which provides one of the main sources for the life of Alexander the Great.
• the epitome of Book IV of Apollodorus of Athens' Bibliotheke or Library which was a comprehensive encyclopaedia of Greek mythology.