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.
Like other PAP (Positive Airway Pressure) machines, the APAP machine is a device that is connected with a non-invasive mask to a pressure generator that is designed to deliver air pressure to keep your airways open while you sleep.