The meaning of the Acronym SPD is...

SPD is

• Shimano Pedaling Dynamics
• Strange Pedal Detachment
• Shimano Pedaling Dynamic

More Meanings For SPD:

• Standard Procedural Database
• Speedo Scalable font
• Single Programming Document
• Security Policy Distribution
• Serial Presence Detect
• So Positively Demonic
• Southern Polar Distance
• Suspended Particle Device
• Silicon Photo Diode
• Symmetric Positive Definite
• Symmetric Positive Definite Matrices
• Symmetric Positive Definite matrix
• Shizoid Personality Disorder
• Solar Patrol Delta
• Space Patrol Delta

SPD is also in:

• Astronomy
• Chat
• Chemistry
• Databases
• Electronics
• File Extensions
• General
• Mathematics
• Psychology
• Science Fiction
• Security
• Telecom