WordWeb Online

1. Fundamental
   "the grassroots factor in making the decision"
    
2. Of or involving the common people as constituting a fundamental political and economic group
   "a grassroots movement for nuclear disarmament"

1. The essential foundation or source
   "the problem was attacked at the grass roots"
    
2. The common people at a local level (as distinguished from the centres of political activity)

See also: basic, common

Type of: common people, folk, folks, foundation

Encyclopedia: Grassroots