what part of no don't you understand?

what part of no don't you understand?

I mean no, and that’s that. This flat denial dates from the late 1900s. It gained currency with a popular song, “What part of no don’t you understand? To put it plain and simple I’m not into one-night stands” (recorded by country music singer Lorrie Morgan, 1992; lyrics by Wayne Perry and Gerald Smith). Also see won't take no for an answer.
See also: no, of, part, what