2) A derogatory term used by locals around a military installation to describe military personnel that roam around town hitting on all the local women. May be men, depending on the "Baser's" gender.
The term "Baser" is also used by older/more experienced military personnel to describe their subordinates who perform these sort of actions.
"These basers are getting out of control in here. One was hitting on my girlfriend!"
SSG Oakes:"Did you see your unit in town the other day, SSG Williams?"
SSG Williams: "Ya, well, we all acted like basers at one point or another."