Regarding the music notation symbol "simili"

Question

I have been researching the music notation symbol "simili" after coming across it in the piano score for Debussy's "Passepied" from the "Suite bergamasque".
The score uses "simili" as the continuation symbol for staccato instead of the more common "simile".

My findings are as follows:

• The possibility that "simili" is a misspelling of "simile" is unlikely as it appears in multiple editions of the score.
• The possibility that "simili" is the plural of the Italian word "simile" is contradicted by the fact that other composers of this era used "simile" in their scores.
  Additionally, Debussy was a French speaker, so he was more likely to follow French musical standards.
• The possibility that "simili" comes from the Esperanto word for "synonymous" is supported by the fact that the publication of "Passepied" (1890-?) overlaps with the announcement of Esperanto in 1887.
  However, it is unclear why Debussy would choose to use Esperanto in his score when other musical symbols are in Italian.
• The possibility of a mistake by the publisher or editor is uncertain since "simili" appears in the original manuscript.

Therefore, the reason for Debussy's use of "simili" instead of "simile" remains unclear.
If anyone has any information on this matter, please let me know.

This question was translated from Japanese, please let me know if you find any expressions that were not conveyed.

Answer 1

The Dolmetsch music dictionary: Sf - Si, list simili as the plural form of simile:

simile (s.), simili (pl.)	(Italian, literally 'similar') an instruction to continue with some effect or technique

Answer 2

In my 'bible' (Oxford Companion to Music), both simili and simile are quoted as plurals from Italian, so it seems either is acceptable.