1 definition by Kayo

Top Definition
short for "Operation Black Mesa". Its a HL2 mod that is recreating "Opposing forces" for HL1.
OpBM is a remake of "Opposing forces"
by Kayo March 02, 2007

Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from daily@urbandictionary.com. We'll never spam you.