GS Definition

abbreviation
General Schedule (civil service classification system)
Webster's New World
General staff.
Webster's New World
General secretary.
Webster's New World
Ground speed.
Webster's New World

The ccTLD for South Georgia and the South Sandwich Islands as assigned by the IANA.

Wiktionary
symbol

(metrology) Symbol for the gigasecond, an SI unit of time equal to 109 seconds.

Wiktionary