X Yy Z Y2K (Year 2000) (or Millennium Bug) Issue Yard (yd) Yaw Year-on-Year (YoY) Growth Rate Year-on-Year (YoY) Change Year-to-Date Data Yeast Yellow Fever Yield Yield Curve Yield Point Yield Strength Yield to Maturity (YTM) Yoke Youthquake Ytterbium (Yb) Yttrium (Y) Yurt X Definition Directory Z