ear·nest /'ər-nəst/ n [Anglo-French ernes(t) erles, alteration of Old French erres, plural of erre pledge, earnest, alteration of Latin arra, short for arrabo, from Greek arrhabōn, of Semitic origin]: something of value given by a buyer to a seller to bind a bargain
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.