1890s style (3,7)
I believe the answer is:
art nouveau
'1890s style' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for art nouveau that I've seen before include "Intricate style of decoration" , "1890s design style" , "European designs" , "French school of painting and architecture of the 1880s" , "Design style used by Charles Rennie Mackintosh, say" .)