1. See bottom fish. 2. a person who functions or seeks to gain at the lowest level of an activity: bottom feeders who buy undervalued stocks; social bottom feeders hanging out in seedy bars. 3. a person who appeals to base instincts: a bottom feeder who directs cheap horror films; Gossip columnists are the bottom feeders of journalism.Also calledbottom-fisher(for defs. 2, 3).