We don't have synonyms for orchestre yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are orchestra, orchestrate and orchestia.
(n) :
Obsolete form of orchestra. [(music) A large group of musicians who play together on various instruments, usually including some from strings, woodwind, brass and/or percussion; the instruments played by such a group.]
(n) :
Obsolete form of orchestra. [(music) A large group of musicians who play together on various instruments, usually including some from strings, woodwind, brass and/or percussion; the instruments played by such a group.]