From BiblePortal Wikipedia

Smith's Bible Dictionary [1]

Shad'da-i. (The Mighty). An ancient name of God, rendered "Almighty", everywhere in the Authorized Version, is found in connection with el , "God", El Shaddai , being then rendered, "God Almighty". By the name, or in the character of El-Shaddai, God was known to the patriarchs,  Genesis 17:1;  Genesis 28:3;  Genesis 43:14;  Genesis 48:3;  Genesis 40:25, before the name Jehovah , in its full significance, was revealed.  Exodus 6:3. See God .

Fausset's Bible Dictionary [2]

("ALMIGHTY".) (See God .) Gesenius derives from Shad , Shaadad , "to be strong."  Isaiah 13:6 plays on similar sounds, "destruction from the Almighty," Shod ("devastating tempest") from Shadday . Rashi and the Talmud (Chagiga, 12, Section 1) from Sh "He who is," and Day "allsufficient."

Holman Bible Dictionary [3]

AlmightyGod Of The FathersNames Of God

Hastings' Dictionary of the Bible [4]

Shaddai . See art. God, 2 ( c ).

Morrish Bible Dictionary [5]

See GOD.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [6]

(Heb. Shadday', שִׁדֵּי , in pause שִׁדָּי ), an ancient name of God, rendered "Almighty" everywhere in the A.V. In all passages of Genesis except one ( Genesis 49:25), in  Exodus 6:3, and in  Ezekiel 10:5, it is found in connection with אֵל , El, "God," El Shaddai being there rendered "God Almighty," or "the Almighty God." It occurs six times in Genesis ( Genesis 17:1;  Genesis 28:3;  Genesis 35:11;  Genesis 43:14;  Genesis 48:3;  Genesis 49:25), once in Exodus ( Exodus 6:3), twice in Numbers ( Numbers 24:4;  Numbers 24:16), twice in Ruth ( Ruth 1:20-21), thirty- one times in Job, twice in the Psalms ( Psalms 68:14 [15];  Psalms 91:1), once in Isaiah ( Isaiah 13:6), twice in Ezekiel ( Ezekiel 1:24;  Ezekiel 10:5), and once in Joel ( Joel 1:15). In Genesis and Exodus it is found in what are called the Elohistic portions of those books, in Numbers in the Jehovistic portion, and throughout Job the name Shaddai stands in parallelism with Elohim, and never with Jehovah. By the name or in the character of El Shaddai, God was known to the patriarchs to Abraham ( Genesis 17:1), to Isaac ( Genesis 28:3), and to Jacob ( Genesis 43:14;  Genesis 48:3;  Genesis 49:25) before the name Jehovah, in its full significance, was revealed ( Exodus 6:3). By this title he was known to the Midianite Balaam ( Numbers 24:4;  Numbers 24:16), as God the Giver of Visions, the Most High (comp.  Psalms 91:1); and the identity of Jehovah and Shaddai, who dealt bitterly with her, was recognized by Naomi in her sorrow ( Ruth 1:20-21). Shaddai, the Almighty, is the God who chastens men ( Job 5:17;  Job 6:4;  Job 23:16;  Job 27:2); the just God ( Job 8:3;  Job 34:10), who hears prayer ( Job 8:5;  Job 22:26;  Job 27:10); the God of power who cannot be resisted ( Job 15:25), who punishes the wicked ( Job 21:20;  Job 27:13), and rewards and protects those who trust in him ( Job 22:23;  Job 22:25;  Job 29:5); the God of providence ( Job 22:17;  Job 22:23;  Job 27:11) and of foreknowledge ( Job 24:1), who gives to men understanding ( Job 32:8) and life ( Job 33:4): "excellent in power, and in judgment, and in plenty of justice," whom none can perfectly know ( Job 11:7;  Job 37:23). The prevalent idea attaching to the name in all these passages is that of strength and power, and our translators have probably given to "Shaddai" its true meaning when they rendered it "Almighty."

In the Targum throughout, the Hebrew word is retained, as in the Peshito- Syriac of Genesis and Exodus, and of  Ruth 1:20. The Sept. gives Ἱκανός , Ἰσχυρός , Θεός , Κύριος , Παντοκράτωρ , Κύριος Παντοκράτωρ , Τὰ Πάντα Ποιήσας ( Job 8:3), Ἐπουράνιος ( Psalms 68:14 [15]), Θεὸς Τοῦ Οὐρανοῦ ( Psalms 91:1), Σαδδαϊ v ( Ezekiel 10:5), and Ταλαιπωρία (Joel i, 15). In  Job 29:5 we find the strange rendering Ὑλώδης . In Genesis and Exodus "El Shaddai" is translated Θεός Μου , or Σου , or Αὐτῶν , as the case may be. The Vulgate has Omnipotens in all cases except Dominus ( Job 5:17;  Job 6:4;  Job 6:14;  Isaiah 13:6), Deus ( Job 22:3;  Job 40:2), Deus Coeli ( Psalms 91:1), Sublimis Deus ( Ezekiel 1:24), Colestis ( Psalms 68:14 [15]) , Potens ( Joel 1:15), and Digne ( Job 37:23). The Veneto-Greek has Κραταιός . The Peshito-Syriac, in many passages, renders "Shaddai" simply "God," in others Chasino, "strong, powerful" ( Job 5:17;  Job 6:4; etc.), and once Eloyo, "Most High" ( Job 6:14). The Samaritan version of  Genesis 17:1 has for "El Shaddai" "powerful, sufficient," though in the other passages of Genesis and Exodus it simply retains the Hebrew word; while in  Numbers 24:4;  Numbers 24:16, the translator must have read שָׂדֶה , sadeh, "a field," for he renders "the vision of Shaddai" "the vision of the field," i.e. the vision seen in the open plain. Aben-Ezra and Kimchi render it "powerful." The derivations assigned to Shaddai are various. We may mention, only to reject, the Rabbinical etymology which connects it with דִּי , Dai, "sufficiency," given by Rashi (On  Genesis 17:1), "I am he in whose Godhead there is sufficiency for the whole creation;" and in the Talmud ( Chagiga, fol. 12, Colossians 1), "I am he who said to the world, Enough!" According to this, שִׁדִּי = אֲשֶׁר דִי , "He who is sufficient," "the all-sufficient One;" and so "He who is sufficient in himself," and therefore self existent. This is the origin of the Ἱκανός of the Sept., Theodoret, and Hesychius, and of the Arabic alkafi of Saadias which has the same meaning. Gesenius (Gram. § 86, and Jesaia 13:6) regards שִׁדִּי , shaddai, as the plural of majesty, from a singular noun, שִׁד , Shad, root שָׁדִד , shadad, of which the primary notion seems to be "to be strong" (Furst, Handwb. ) . It is evident that this derivation was present to the mind of the prophet from the play of words in  Isaiah 13:6. Ewald ( Lehrb. § 155 c, 5th ed.) takes it from a root שָׁדָה = שָׁדִד , and compares it with דִּיָּי , Davvai, from דָּוָה , Davah, the older termination יִי being retained. He also refers to the proper names יַשִׁי , Yishai (Jesse), and בִּוִּי , Bavvai ( Nehemiah 3:18). Rodiger (Gesen. Thesaur. s.v.) disputes Ewald's explanation, and proposes, as one less open to objection, that Shaddai originally signified "my powerful ones," and afterwards became the name of God Almighty, like the analogous form Adonai. In favor of this is the fact that it is never found with the definite article, but such would be equally the case if Shaddai were regarded as a proper name. On the whole there seems no reasonable objection to the view taken by Gesenius, which Lee also adopts (Gram. § 139, 6).

Shaddai is found as ant element in the proper names Ammishaddai, Zurishaddai, and possibly also in Shedeur there may be a trace of it.

Kitto's Popular Cyclopedia of Biblial Literature [7]

Shad´dai, an epithet or name applied to Jehovah. In it is given as El-Shaddai in the Authorized Version; but is everywhere else rendered by 'Almighty,' which is its true signification.

International Standard Bible Encyclopedia [8]

shad´ā́ - ı̄ , shad´ı̄ . See God , Names Of , II., 8.