The meaning of the Acronym ISR is...

ISR is

• Installation Status Report
• Individual Soldier Radio
• Intelligence, Surveillance, and Reconnaissance

More Meanings For ISR:

• Interrupt Service Routine
• Interrupt Segment Register
• Interrupt Space Register
• Interrupt Service Routine
• Information Storage and Retrieval
• Intermediate Session Routing
• Integrated Switch Router
• Incremental Software Release
• In-Situ Rinse
• Ice Sheet Reconstruction
• Initial State Radiation
• Institute for Sensory Research
• Intercept Stabilize And Resolve
• Illegal Street Racing
• Illegal Street Racer

ISR is also in:

• Assembly
• Drivers
• Electronics
• General
• Meteorology
• Networking
• Physics
• Software
• Unfiled
• Universities