Abbreviation of Put hand on mouth, used to express the action itself which refelcts shock,humour or the witnessing of an intense event.
by david sjarkov April 13, 2008
Brother 1: I just tore your Spiderman #1
Brother #2: PHOM!!!!!!!!!! PHOM PHOM!!!!!! I'm gonna phom you up!
Brother #2: PHOM!!!!!!!!!! PHOM PHOM!!!!!! I'm gonna phom you up!
by Maverick September 03, 2003