GA
1. What does GA stand for?
Good afternoon
Example
"GA, how are you doing today?"

GA means good afternoon
Related Slang
Usage
Last Updated: February 22, 2018
2. What does GA stand for?
Go ahead
Gives permission to do something or can be used to "egg" another person on.
Example
"GA, make my day."
Related Slang
Usage
Last Updated: August 7, 2013
GA is an acronym for "good afternoon", which is a saying typically used from noon to 5pm to greet someone. The acronym is most often seen online or in text messages.
GA is usually used in the beginning of a formal message to be polite to the recipient. It is most likely used by an older person since there are plenty of more fun and casual ways that younger people use instead.