Reuben Look up Reuben at Dictionary.com
masc. proper name, Old Testament eldest son of Jacob and name of the tribe descended from him, from Greek Rouben, from Hebrew Reubhen, probably literally "Behold a son," from reu, imper. of ra'ah "he saw" + ben "a son." The reuben sandwich (1956) is "not obviously connected" with the sense in rube [OED].