Strong's #7263: regeb (pronounced reh'-gheb)
 from an unused root meaning to pile together; a lump of clay:--clod.
Brown-Driver-Briggs Hebrew Lexicon:
 
  regeb 
 
 1) clod (of earth)
 
  Part of Speech: noun masculine
Relation: from an unused root meaning to pile together
Usage:
This word is used 2 times:
Job 21:33: " The clods of the valley shall be sweet unto him, and every man shall draw after him, as there are innumerable"
Job 38:38: "When the dust groweth into hardness,  and the clods cleave fast together?"