Derived from grommet, description of a young surfer. Usually issued in a positive way to describe a young local surfer who really rips.
(Surf Lingo Lexicon. www.raptionary.comより引用)
When I was a young grom trying to get through a few rounds in inter-club and schoolboy surf comps, there was no such thing as preparation for an event, not physically or mentally.
You surfed as much as you could and tried to not get too wasted the night before which, come to think of it, is more or less the way it is now in the old farts’ divisions.
By the time pro surfing became a reality in the early 1970s, I’d wisely handed in the jersey and picked up a pen instead, which gave me an excuse to be hanging around at most of the landmark events that led to a world pro tour being instigated in 1977.
(Phil Jarrat. The new wave of elite training. The Noosa Journal. August 10, 2010.)