E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Smart, dandified. Hall tells us it is a contraction of Prussian-like, à la Prusse, and gives the subjoined quotation:
After them came Si Edward Hayward, and with him Sir Thomas Parre, in doublets of crimson velvet, faced on the breast with chains of silver, and over that short cloaks of crimson satin, and on their heads hats after dancers fashion, with feathers in them. They were apparelled after the fashion of Prussia or Spruce.
In confirmation of this it may be mentioned that Spruce leather is certainly a corruption of Prussian leather; Spruce-beer is beer made from the Spruce or Prussian fir, and Danzig, in Prussia, is famous for the beverage.