Y

Y stands for Why
Y stands for Year
Y stands for Yahoo! (Internet search engine)
Y stands for Yes
Y stands for Yellow
Y stands for Corporation (IRB)
Y stands for Income (economics)
Y stands for Economy (class airfare)
Y stands for Business Class (Air Freight; also see C, Economy Class)
Y stands for Yard
Y stands for Yankee (aviation letter code)
Y stands for Yen (Japanese currency)
Y stands for Yukon Territory (postal code designation, Canada)
Y stands for Y Chromosome
Y stands for Bundeswehr (German Armed Forces; number plate)
Y stands for Tyrosine (amino acid)
Y stands for Yaw
Y stands for Yttrium
Y stands for Yeoman
Y stands for Luminance (signal)
Y stands for Consolidated-Vultee Aircraft Corporation (manufacturer’s symbol; now Convair)
Y stands for Yotta- (prefix, 10^24 or septillion)
Y stands for Yocto (prefix for one septillionth, 10^ -24)
Y stands for Male Chromosome
Y stands for Yukon Standard Time
Y stands for YMCA or YWCA (Young Men’s Christian Association or Young Women’s Christian Association)
Y stands for Search and Rescue Unit (SRU) Error (US DoD)
Y stands for US DoT tire speed rating (188 mph)
Y stands for Vertical axis in Cartesian coordinate system
Y stands for Navigational error of search craft
Y stands for Prototype Aircraft Designation