What does Z stand for?

What does Z mean?

Z	Zzzzzz (falling asleep at the keyboard) Internet » Chat
Z	Zartan Miscellaneous » Science Fiction
Z	Venator Group, Inc. Business » NYSE Symbols
Z	Zivilversion Computing » Software
Z	Flash Precedence Governmental » Military
Z	Unit of Sleep Miscellaneous » Unit Measures
Z	Zulu Time (Coordinated Universal Time [UTC] / 'Greenwich Mean Time' ) Regional » Time Zones
Z	A Hazard Level Governmental » Environmental
Z	Aircraft Symbol prefix – Planning Governmental » Military
Z	Aircraft Symbol prefix – Planning Governmental » NASA
Z	Aircraft Symbol prefix – Planning Governmental » Transportation
Z	Compressed file archive.Z Computing » File Extensions
Z	Unix Compressed file archive.z (binary) Computing » File Extensions
Z	Impedance Governmental » NASA
Z	form Z (polar make; make) bar contactor Academic & Science » Electronics
Z	Zener diode Computing » Hardware
Z	Zener diode Academic & Science » Electronics
Z	Depth axis Academic & Science » Physics
Z	Zone Governmental » NASA
Z	Zulu Time (Greenwich Mean Time / Universal Time) Governmental » NASA
Z	Z-axis direction Governmental » NASA
Z	Normal Acceleration (Load Factor) Governmental » NASA
Z	Zulu time Governmental » Military