Posted in Internet Slang, Pop Culture, Science, Sports YST stands for Yoroiden Samurai Troopers (Japanese animation series created in the 1980s) YST stands for Yamaha Active Servo Technology (speakers) YST stands for Yahoo! Search Technology YST stands for Youth Sport Trust (UK) YST stands for Yukon Standard Time (GMT-0900) YST stands for Yellow Starthistle YST stands for You Sexy Thing YST stands for Yolk Sac Tumor YST stands for Youth Service Team