GSY Views 10 meanings found GSY is used as a short code for several places such as Guernsey and Grimsby, appears in scientific timelines as Galactic Standard Year, shows up in informal slang, and is occasionally seen in company names. Miscellaneous Go Screw Yourself Garden State Yoga Greater Scranton Ymca Community Global Startup Youth Academic & Science Galactic Standard Year Regional Grimsby, England, UK Guernsey Business Guest Supply, Inc. Goeasy LTD. Sports Gym Sports for Youth