Definition of niggling for English Language Learners. : causing you to feel a slight pain or to be worried or annoyed for a long time.
What is PPAP? The Production Part Approval Process (PPAP) is a standardized process in the automotive and aerospace industries that helps manufacturers and suppliers communicate and approve production designs and processes before, during, and after manufacture.
CPAP is an acronym for Continuous Positive Airway Pressure; a device that provides a fixed amount of pressurized air and is used for the treatment of obstructive sleep apnea, sleep disordered breathing and snoring.