What is meant by PID?

Answer 1

In the Navy in the 80's and 90's it was an acronym for Personal Injury or Death. It was the title of a safety report that needed to be filed with the Navy Safety Center after an on the job injury. I'm sure that it has some other meanings as well.

Answer 2

It could mean Pelvic Inflammatory Disease.

When a woman's Fallopian tubes become infected possibly making her sterile.

This disease is a result of the sexually transmitted infection Chlamydia.

Answer 3

Asumming this query does apply to electronics, PID stands for "proportional-intergral-derivative, it relates to the automated process of maintaining an accurate setpoint by adjusting control outputs".

A proportional-integral-derivative controller (PID controller) is a generic control loop feedback mechanism (controller) widely used in industrial control systems. A PID controller attempts to correct the error between a measured process variable and a desired setpoint by calculating and then outputting a corrective action that can adjust the process accordingly and rapidly, to keep the error minimal.

Answer 4

PID may also mean personal identification document.