A rejection of an applicant's membership in a private organization, such as a club or fraternity. The term is derived from the traditional practice of members voting anonymously on admitting new members, using either a white marble (acceptance) or a black marble (denial). Acceptance must be unanimous; therefore, one black marble in the ballot box is enough to keep the applicant out of the organization.
Note: The term is now applied generally to efforts — especially unreasonable or vengeful actions — to keep a people or groups out of organizations they wish to join.
To punish someone by denial of work, boycotting of products, etc •Both terms come fr the 1700s and meant ''to ostracize''; the modern specialized sense appears to have developed in the labor troubles of the 1890s: Some members of the Twilight Zone movie crew say they are being blackballed