Hastings' Dictionary of the Bible 
Abrech . A word of doubtful signification, tr. [Note: translate or translation.] ‘Bow the knee,’ in AV [Note: Authorized Version.] and RV [Note: Revised Version.] ( Genesis 41:43 ‘then he made him [Joseph] to ride in the second chariot which he had; and they cried before him, Bow the knee; and he set him over all the land of Egypt’). The word should be either Hebrew or Egyptian. An Assyr. [Note: Assyrian.] etymology has been proposed, viz. abarakku , the title of one of the highest officials in the Assyrian Empire, but no such borrowings from Assyria are known in Egypt. Hebrew affords no likely explanation. Egyptian hitherto has furnished two that are possible: (1) ‘Praise!’ but the word is rare and doubtful; (2) abrak , apparently meaning ‘Attention!’ ‘Have a care!’ (Spiegelberg). The last seems the least improbable.
F. Ll. Griffith.
Fausset's Bible Dictionary 
( Genesis 41:43). Translated "bow the knee" in English Bible. Others translate "a pontifical," or "pure prince," a common title in ancient Egyptian tombs; Origen and Jerome, "a native Egyptian." Thus Abrech will be a proclamation of Joseph's naturalization, a requisite for his executing successfully his great, undertaking among a people most jealous of foreigners. Canon Cook (Speaker's Commentary) makes it imperative, from the Egyptian," Rejoice thou;" but Harkevy understands it as Αp-Rach , "Chief of the Rech", or "men of learning."
Cyclopedia of Biblical, Theological and Ecclesiastical Literature 
(Heb. abrek', אִבְרֵךְ , Sept. Κῆρυξ , Vulg. Venuflecterent), a word that occurs only in the original of Genesis 41:43, where it is used in proclaiming the authority of Joseph. Something similar happened in the case of Mordecai, but then several words were employed ( Esther 6:11). If the word be Hebrew, it is probably an imperative (not directly, Buxtorf, Thes. Gramm. p. 134; nor the first person future, as explained by Aben- Ezra, but the infinitive absolute used imperatively, Gesenius, Thes. Heb. p. 19) of בָּרִךְ , in Hiphil, and would then mean, as in our version, "bow the knee" (so the Vulg., Erpenius, Luther, Aquila, and the Ven. Gr. version). We are indeed assured by Wilkinson (Anc. Egyptians, 2, 24) that the word abrek is used to the present day by the Arabs when requiring a camel to kneel and receive its load. But Luther (subsequently) and others (e.g. Onkelos, the Targum, Syr. and Persic versions) suppose the word to be a compound of אבאּרךְ , " The Father Of The State," and to be of Chaldee origin. The Sept. and Samar. understand vaguely A Herald. It is, however, probably Egyptian, slightly modified so as to suit the Hebrew; and most later writers are inclined with De Rossi (Etym. Egypt. p. 1) to repair to the Coptic, in which Aberek or Abrek means " Bow The Head" — An interpretation essentially agreeing with those of Pfeiffer (Opp. 1, 94) and Jablonski (Opusc. 1, 4, 5, ed. Water). (See Salutation). But Origen (Hexapla, 1, 49, ed. Montfaucon), a native of Egypt, and Jerome (Comment. in loc.), both of whom knew the Semitic languages, are of the opinion that Abrech means "a native Egyptian;" and when we consider how important it was that Joseph should cease to be regarded as a foreigner [ (See Abomination) ], it has in this sense a significance, as a proclamation of naturalization, which no other interpretation conveys (see Ameside, De Abrech Aegyptior. Dresd. 1750). Osburn thinks the title still appears in Joseph's tomb as Hb-Resh, "royal priest" (Mon. Hist. Of Eg. 2. 90).
International Standard Bible Encyclopedia 
ā´brek : Transliteration of the Hebrew אברך , 'abhrēkh , in Genesis 41:43 the Revised Version, margin, of which both the origin and meaning are uncertain. It was the salutation which the Egyptians addressed to Joseph, when he was made second to Pharaoh, and appeared in his official chariot.
(1) The explanations based upon Hebrew derivation are unsatisfactory, whether as the King James Version "bow the knee," from ברך , bārakh (hiphil imperative) or marginal "tender father," or "father of a king" of the Targum. The form as Hiphil Imperative instead of הברך , habhrēkh , is indefensible, while the other two derivations are fanciful.
(2) The surmises of Egyptologists are almost without number, and none are conclusive. Skinner in his Commentary on Genesis selects "attention!" after Spiegelberg, as best. Speaker's Commentary suggests "rejoice thou" from ab - nek . BDB gives preference to the Coptic a - bor - k , "prostrate thyself."
(3) The most satisfying parallel is the Assyrian abarakku , meaning "grand vizier" or "friend of a king," as suggested by Fried. Delitzsch; for Babylonian laws and customs were dominant in western Asia, and the Hyksos, through whom such titles would have been carried into Egypt, were ruling there at that time.