The meaning of SOL as an abbreviation is “shit out of luck”.
It is used to describe extremely desperate and hopeless situations or misfortune in general.
“Sol” was conceived sometime during the late 90’s or early 2000’s as a way of shortening the slang expression.
The growing phenomenon of the internet and text messaging gave people an excellent opportunity to give voice to their discontent about their fate with a mere three letters.
The acronym as a slang abbreviation was first defined on Urban Dictionary in 2003.
As of January 26th, 2020, one may encounter “sol” in texts received on WhatsApp, posts on Facebook or tweets on… well, not Reddit.