So I asked on Twitter what the term meant and scratched told me it's used a lot in the HBO series Generation Kill and probably means "On the Move."
He was right.
Here's a list of Iraqi theater military terms: Iraq’s battlefield slang
Oscar Mike: On the move (Marine lingo).
I love these:
Echelons above reality: Higher headquarters where no one has an idea about what is really happening.
Embrace the suck: Phrase heard in OIF1 (the original Operation Iraqi Freedom force). Translation: The situation is bad, but deal with it.
Geardo: Derogatory term for the guy who has to have all the latest and greatest gear on his uniform, even though he does not know how to use it.
Groundhog Day: Every day of your tour in Iraq.
Johnny Jihad: Slang for a Muslim or Muslim combatant.