Monier-Williams:
pra-ṇava: See pra-ṇu. pra-°ṇava b (or pra-ṇ°), mf. (ifc. f(ā). ) the mystical or sacred syllable om
pra-nu: (√nu) P. Ā. -navati, °te, to roar, bellow, sound, reverberate, RV. ; AV. ; P. -ṇauti, to make a humming or droning sound; (esp.) to utter the syllable om, Br. ; ChUp. ; ŚrS.
