Noun
market class (plural market classes)
(agriculture) A commodity, usually produced on farms and part of a larger category. Products within a market class have similar physical characteristics, are grown or raised under similar conditions, and are bought and sold under similar terms and conditions.
Illegal immigrants are beginning to comprise a black market class of workers in our society, jeopardizing the financial health of companies which play by the rules, while themselves vulnerable to the exploitation by those willing to take advantage of their illegal status. Spencer Bachus