A person who
will get the job done by ANY means. A grubster is tough, mean, and determined. The first time I heard the term, it was a nickname for a
football linebacker at my highschool. His name was Bing which didn't sound very tough so his team mates called him grubster. He would hit guys so hard that the "
pop" sound would echo through the stands. Twenty years later, everyone I know still uses the term. I even hear people I don't know use the term.