The Collaborative International Dictionary
Duettino \Du`et*ti"no\, n. [It ., dim. fr. duetto a duet.] A duet of short extent and concise form. [1913 Webster] ||
Wiktionary
n. A duet of short extent and concise form.
Wikipedia
A duettino is an unpretentious duet with a concise form. Wolfgang Amadeus Mozart offers several well-known examples of the type, including "La ci darem la mano" from Don Giovanni and "Duettino No. 3" from La clemenza di Tito, a song only twenty-four measures long. He also described "Via resti servita" in The Marriage of Figaro as a duettino.
By the time of Gioachino Rossini, a duettino was a common part of the introduction of the Farsa opera genre. Rossini composed several pieces in the form.
Usage examples of "duettino".
As she is about to leave the room, Marcellina meets Susanna, and the two make a forced effort to conceal their mutual hatred and jealousy in an amusing duettino ("Via resti servita, madama brillante!