noun
second part (of three); middle volume
Used for the middle installment of a three-part work, such as a trilogy or a three-volume set.
この三部作の中編が一番面白い。
The second part of this trilogy is the most interesting.
noun
novella; short novel
Abbreviation of 中編小説. Refers to a work of fiction longer than a short story but shorter than a full-length novel.
See also:
彼の新作は中編で、一気に読める長さだ。
His new work is a novella, a length you can read in one sitting.
Compound of 中 (middle) and 編 (volume, part). The novella sense is an abbreviation of 中編小説.