a short novel or substantial short story, usu more complex than a short story
a substantial short story or narrative tale, esp of a satirical nature
As a short prose narrative or long tale, the novella goes back to Boccaccio's Decameron (1471) and earlier. For the Romantics it became a form of long short story, poetic and fantastic, more precise than the novel, focused around a single event. Striking modern examples of novellas are Conrad's Heart of Darkness (1902), Kafka's Metamorphosis (1912) and Mann's Death in Venice (1913) — Professor Malcolm Bradbury
[Italian novella; see novel1]