The meaning of the Acronym PSI is...

PSI is

• Philanthropic Service for Institutions
• Poetry Slam Incorporated
• Psychological Society of Ireland

More Meanings For PSI:

• Precise Stylus Input
• Packetnet System Interface
• Pounds per Square Inch
• Pounds per Square Inch
• Position Specific Iterated
• Pollution Standard Index
• Pounds per Square Inch
• Pounds per Square Inch
• Probability, Statistics, and Inference
• Personalized System of Instruction
• Psychology Slander Intuition
• Post Secondary Institution
• Psychology Student Instructor
• Parapsychology Studies Institute
• Pressure Stuck Inside

PSI is also in:

• Chemistry
• Electronics
• Funnies
• General
• Mathematics
• Meteorology
• Networking
• Ocean Science
• Physics
• Universities