Sterling File Gateway (SFG): An Intelligent, Centralized Gateway for Managing Edge-Based File Transfers. acronym for 'so far gone'. What does SFG mean? This page is about the various possible meanings of the acronym, abbreviation, shorthand or slang term: SFG. SFG may refer to: In military use: Special Forces Group (Belgium) Special Forces Group (Japan) Special Forces (United States Army)#Special Forces groups.