Green’s Dictionary of Slang

(US) showy, high-class.

1899		Ade Fables in Sl. (1902) 37: It would be a Big Help to the Poor and Uncultured to see what a Real Razmataz Lady was like.
1914		Ade ‘The New Fable of the Wandering Boy’ in Ade’s Fables 136: It was evident that he had not been travelling with the Real Razmataz Rompers.
1953		S. Bellow Augie March (1996) 58: Noble marbled, footmanned, razmataz, furnished-for-pontiffs lakeside joints.
1960		P. Rabe Murder Me for Nickels (2004) 27: It [i.e. a jukebox] was the razzmatazz type, blinking red, white and blue.