Meaning of the Sanskrit Word: pranavah

  praṇavaḥ—the three letters A.U.M.    Bg 7.8
  praṇavaḥ—the oṁkāra    SB 3.12.44
  praṇavaḥ—oṁkāra    SB 9.14.48

Can't find any compound Sanskrit words containing pranavah.