We don't have synonyms for vernissage yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are vernissages.
(n) :
the day before the opening of an exhibition when paintings are varnished and retouched; a private viewing of an exhibition before it opens to the public
"1893: the artists' association will be forced to advance or delay its vernissage and opening day. -- The Times, 2 May 1893, p.5 col. C"
(n) :
the day before the opening of an exhibition when paintings are varnished and retouched; a private viewing of an exhibition before it opens to the public
"1893: the artists' association will be forced to advance or delay its vernissage and opening day. -- The Times, 2 May 1893, p.5 col. C"