vernissage
Concise Oxford English Dictionary © 2008 Oxford University Press:
vernissage /ˌvɛːnɪˈsɑːʒ/
▶noun (pl. pronounced same) a private view of paintings before public exhibition.
– origin Fr., lit. ‘varnishing’, orig. referring to the day prior to an exhibition when artists were allowed to retouch and varnish hung work.
'vernissage' also found in these Oxford entries:

