Definition of pop-pop in US English:

pop-pop

adverb

  • Especially of the firing of a gun or guns: with a repeated series of short abrupt explosive sounds. Also as interjection: representing such sounds.

noun

  • A repeated series of short abrupt explosive sounds, especially of a gun or guns being fired.

adjective

  • That makes such a series of sounds; popping.

Origin

Late 18th century. Reduplication of pop. With use as adverb compare earlier pop.

Pronunciation

pop-pop

/ˈpɒpˌpɒp/