He was granted a conditional discharge and ordered to stay away from the bar where the incident occurred last year.
Thomas, 38, a Northeast District officer pleaded guilty to a non-criminal harassment charge for the February 2008 incident at the Town Ballroom. He had been charged with menacing.
After prosecutor Susan H. Sadinsky told City Judge Patrick M. Carney that the non-criminal plea was acceptable, Thomas pleaded guilty.
The judge reminded the 10-year police veteran that being a police officer “is a career, not a job.”
Thomas also has been suspended without pay for 22 days on a departmental plea.
Thomas and his attorney could not be reached to comment following the Friday morning court session.
At the request of the prosecutor, Carney also issued a one-year order of protection to three Town Ballroom employees, instructing Thomas to stay away from them during that period.