Raca
a term of reproach derived from the Chaldee reka, worthless. ("Raca denotes a certain looseness of life and manners, while 'fool,' in the same passage, means a downright wicked and reprobate person.") Mt 5:22
Bibliography Information Smith, William, Dr "Definition for 'Raca' Smiths Bible Dictionary". bible-history.com - Smiths; 1901.