Debussy used the word as a mix of a number of different meanings – to signify the several levels of this piece. He wanted to evoque a feeling of antiquity and adventure. So:
1. “Bergamasche” – a renaissance dance often found in Frescobaldi’s suites. Also a peasant dance from the region of Bergamo (Italy).
2. “Bergame” a kind of tapestry originating from the city of Bergamo. This city is older than Rome (about 40 km from Milan)
3. “Bergamasque” also refers to the region of Bergamo and its inhabitants. These guys are famous all over Italy for their rusticity and clumsiness, and this has inspired a whole number of regional dances in Italy. Furthermore it is on them that the character “harlequin” (from the commedia dell arte) is based. Originally Harlequin was the prototype of the shrewd country hick while appearing to be a simpleton. The character is a satyre on the people from Bergamo.
4. Debussy of course had visited Italy many times (as the piano teacher of Nadedja Von Meck’s children – Tchaikovsky’s secret patroness) and had spent 2 years there after receiving the Prix de Rome for composition (1885 – 1887). He was thoroughly knowledgeable about the commedia dell’arte and its characters (Pierrot, Scaramouche, Pulcinella, etc.) The suite was composed in 1890 (published 1903).
5. Finally, the real inspiration for the title comes from Paul Verlaine’s poem “Fêtes galantes”:
“Votre âme est un paysage choisi
Que vont charmant masques et bergamasques,
Jouant du luth, et dansant, et quasi
Tristes sous leurs déguisements fantasques. ”.
(you can read the whole poem here:
https://membres.lycos.fr/jccau/ressourc/biblio/verlaine/fetesgal.htmthe verses above are taken from “Clair de Lune”).
That Debussy was deeply interested in the commedia dell’arte can be seen by the fact that he also composed other pieces relating to it (notably “Masques” – again inspired by Verlaine “masques et bergamasques” and even composed a song cycle based on Verlaines “Fetes Galantes”, and just before he died was considering a work for theatre based on it.)
6. The suite Bergamasque itself is a hommage to the Baroque dance suite, with Clair de lune taking the place of the slow dance (for a similar hommage have a look at Grieg’s Holberg Suite).
7. Finally, the word in English is “Bergomask” (rarely used) and you can find it in Shakespeare’s “Midsummer’s Night Dream” when Botton asks the Duke: “Will it please you to see the epilogue or to hear a Berrgomask dance between two of our companies?”
I hope this helps.
Best wishes,
Bernhard