n. 1 unclean matter that soils. 2 a earth, soil. b earth, cinders, etc., used to make a surface for a road etc. (usu. attrib. : dirt track; dirt road). 3 foul or malicious words or talk. 4 excrement. 5 a dirty condition. 6 a person or thing considered worthless. dirt bike a motor cycle designed for use on unmade roads and tracks, esp. in scrambling. dirt cheap colloq. extremely cheap. dirt-track a course made of rolled cinders, soil, etc., for motor-cycle racing or flat racing. do a person dirt sl. harm or injure a person's reputation maliciously. eat dirt 1 suffer insults etc. without retaliating. 2 US make a humiliating confession. treat like dirt treat (a person) contemptuously; abuse.
[ ME f. ON drit excrement ]