abbreviation sis definition
Freebase(0.00 / 0 votes)Rate this definition: SIS is an acronym that stands for Software Installation Script. It is an archive for Symbian OS, and not an application file, as sometimes believed; the real Symbian application is the .APP or .EXE file within it. By convention .sisx denotes a signed file. There are different ways how a SIS file can be created.