The meaning of the Acronym SIS is...

SIS is

• Secret Intelligence Service

More Meanings For SIS:

• Simple Instruction Set
• Psion Software Installation file
• Saws Information System
• Spectrum Internet Suite
• Shimano Index Shifting
• Sister
• Superconductor Insulator Superconductor
• Safety Instrumented System
• Science Information Systems
• Student Information System
• Sean Is Stupid
• Stupid Impossible Scenarios
• Short-Interval Schedular
• Seti Intercept System
• Single Image Stereogram

SIS is also in:

• Adults
• Assembly
• Chat
• Electronics
• File Extensions
• General
• Software
• Unfiled
• Universities
• USPS