Used to describe a male that is extremely 'nice' to girls and is usually friends with several girls at any given time. The phrase derives from the fact that the person is usually trying to lay the 'groundwork' for future romantic engagements or just a casual one-night stand. This person will often be found preying on other guy's troubled girlfriends or other girls in need of a 'nice' guy to talk to. Example:
GARRY-GROUNDWORK
Meaning of GARRY-GROUNDWORK in English
Slang English vocab. Английский сленговый словарь. 2012