From The Collaborative International Dictionary of English v.0.48:
Flashy \Flash"y\, a. 1. Dazzling for a moment; making a momentary show of brilliancy; transitorily bright. [1913 Webster]
A little flashy and transient pleasure. --Barrow. [1913 Webster]
2. Fiery; vehement; impetuous. [1913 Webster]
A temper always flashy. --Burke. [1913 Webster]
3. Showy; gay; gaudy; as, a flashy dress. [1913 Webster]
4. Without taste or spirit. [1913 Webster]
Lean and flashy songs. --Milton. [1913 Webster]