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.
Point-to-Point Tunneling Protocol. The Point-to-Point Tunneling Protocol (PPTP) is an obsolete method for implementing virtual private networks, with many known security issues. PPTP uses a control channel over TCP and a GRE tunnel operating to encapsulate PPP packets.