Short for "Thank You For Your Service"
A phrase used when addressing a volunteer fireman/EMT usually by a paid firefighter or medic.
Usually snarky, judgmental, and sarcastic in nature.
Look at that guy with the Mainville Volunteer Fire Department "dragon slayer" shirt on. *walks up* "TYFYS - THANK YOU FOR YOUR SERVICE!"
The acronym for 'Thank You For Your Service.' Usually used ironically to express that you did not actually want the service in question. It's also a polite way to say "go fuck yourself you jackbooted thug."
Cop: "I'm citing you for a seatbelt violation. It's a $200 fine but it's for your own good."
Citizen: "TYFYS"
Person 1: Hey, what's up?
Person 2: Well, my dog chewed on my shoe, my dad made eggs and toast and bacon with a little bit too much pepper on the eggs but it's okay because I usually like a little too much pepper on my eggs, I was late for my first class but it's okay because it was Dr. _____ and they don't care but I still felt guilty and...
Person 1: Er, wow. That was quite the lengthy answer.
Person 2: Tyfyt.