An acronym usually used to refer to a giantess or giantess growth, that is, a woman growing incredibly tall, sometimes used in conjunction with the word "virus" to refer to a fictional virus that will make a woman grow taller
Man, those gts pictures sure get me going
I found a pic last night of a gts kim kardashian, and it changed my view on her
Hector: There's a big thing going on in Barstow this weekend.
Charlie: How do you know?
Hector: I GTS'd it.
Charlie: Are there any good strip clubs around there?
Hector: GTS, man!
Definition #1: GTS can be used in conversation when someone wants to challenge another person's knowledge regarding a subject matter at hand.
Definition #2: GTS can also be used completely out of context and randomly stated in conversation or as a comment/post on Facebook.
Definition #1:
Girl: "Dang, Amy Winehouse joined the 27 club. Now there's 6, Cobain, Hendrix, Joplin, Morrison, Winehouse...and, uh, who's the other one?"
Boy: "Hmm, I don't know."