The Collaborative International Dictionary of English v.0.48:

God \God\ (g[o^]d), n. [AS. god; akin to OS. & D. god, OHG. got,
   G. gott, Icel. gu[eth], go[eth], Sw. & Dan. gud, Goth. gup,
   prob. orig. a p. p. from a root appearing in Skr. h[=u], p.
   p. h[=u]ta, to call upon, invoke, implore. [root]30. Cf.
   Goodbye, Gospel, Gossip.]
   1. A being conceived of as possessing supernatural power, and
      to be propitiated by sacrifice, worship, etc.; a divinity;
      a deity; an object of worship; an idol.
      [1913 Webster]

            He maketh a god, and worshipeth it.   --Is. xliv.
                                                  15.
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            The race of Israel . . . bowing lowly down
            To bestial gods.                      --Milton.
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   2. The Supreme Being; the eternal and infinite Spirit, the
      Creator, and the Sovereign of the universe; Jehovah.
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            God is a Spirit; and they that worship him must
            worship him in spirit and in truth.   --John iv. 24.
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   3. A person or thing deified and honored as the chief good;
      an object of supreme regard.
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            Whose god is their belly.             --Phil. iii.
                                                  19.
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   4. Figuratively applied to one who wields great or despotic
      power. [R.] --Shak.
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   Act of God. (Law) See under Act.

   Gallery gods, the occupants of the highest and cheapest
      gallery of a theater. [Colloq.]

   God's acre, God's field, a burial place; a churchyard.
      See under Acre.

   God's house.
      (a) An almshouse. [Obs.]
      (b) A church.

   God's penny, earnest penny. [Obs.] --Beau. & Fl.

   God's Sunday, Easter.
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The Collaborative International Dictionary of English v.0.48:

Act \Act\ ([a^]kt), n. [L. actus, fr. agere to drive, do: cf. F.
   acte. See Agent.]
   1. That which is done or doing; the exercise of power, or the
      effect, of which power exerted is the cause; a
      performance; a deed.
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            That best portion of a good man's life,
            His little, nameless, unremembered acts
            Of kindness and of love.              --Wordsworth.
      [1913 Webster] Hence, in specific uses:
      (a) The result of public deliberation; the decision or
          determination of a legislative body, council, court of
          justice, etc.; a decree, edit, law, judgment, resolve,
          award; as, an act of Parliament, or of Congress.
      (b) A formal solemn writing, expressing that something has
          been done. --Abbott.
      (c) A performance of part of a play; one of the principal
          divisions of a play or dramatic work in which a
          certain definite part of the action is completed.
      (d) A thesis maintained in public, in some English
          universities, by a candidate for a degree, or to show
          the proficiency of a student.
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   2. A state of reality or real existence as opposed to a
      possibility or possible existence. [Obs.]
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            The seeds of plants are not at first in act, but in
            possibility, what they afterward grow to be.
                                                  --Hooker.
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   3. Process of doing; action. In act, in the very doing; on
      the point of (doing). "In act to shoot." --Dryden.
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            This woman was taken . . . in the very act. --John
                                                  viii. 4.
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   Act of attainder. (Law) See Attainder.

   Act of bankruptcy (Law), an act of a debtor which renders
      him liable to be adjudged a bankrupt.

   Act of faith. (Ch. Hist.) See Auto-da-F['e].

   Act of God (Law), an inevitable accident; such
      extraordinary interruption of the usual course of events
      as is not to be looked for in advance, and against which
      ordinary prudence could not guard.

   Act of grace, an expression often used to designate an act
      declaring pardon or amnesty to numerous offenders, as at
      the beginning of a new reign.

   Act of indemnity, a statute passed for the protection of
      those who have committed some illegal act subjecting them
      to penalties. --Abbott.

   Act in pais, a thing done out of court (anciently, in the
      country), and not a matter of record.
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   Syn: See Action.
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WordNet (r) 3.0 (2006):

act of God
    n 1: a natural and unavoidable catastrophe that interrupts the
         expected course of events; "he discovered that his house
         was not insured against acts of God" [syn: act of God,
         force majeure, vis major, inevitable accident,
         unavoidable casualty]

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "act of God":
   certainty, fate, fatefulness, force majeure, indefeasibility,
   ineluctability, inescapableness, inevasibleness, inevitability,
   inevitable accident, inevitableness, inexorability, inflexibility,
   irrevocability, necessity, predetermination, relentlessness,
   sureness, unavoidable casualty, unavoidableness, uncontrollability,
   undeflectability, unpreventability, unyieldingness, vis major



Bouvier's Law Dictionary, Revised 6th Ed (1856):

ACT OF GOD, in contracts. This phrase denotes those accidents which arise
from physical causes, and which cannot be prevented.
     2. Where the law casts a duty on a party, the performance shall be
excused, if it be rendered impossible by the act of God; but where the
party, by his own contract, engages to do an act, it is deemed to be his own
fault and folly that he did not thereby provide against contingencies, and
exempt himself from responsibilities in certain events and in such case,
(that is, in the instance of an absolute general contract the performance is
not excused by an inevitable accident, or other contingency, although not
foreseen by, nor within the control of the party. Chitty on Contr. 272, 8;
Aleyn, 27, cited by Lawrence; J. in 8 T. R. 267; Com. Dig. Action upon the
Case upon Assumpsit, G; 6 T. R. 650 ; 8 T. R. 259; 3 M. & S. 267 ; 7 Mass.
325; 13 Mass. 94; Co. Litt. 206; Com. Dig. Condition, D 1, L 13; 2 Bl. Com.
340; 1 T. R. 33; Jones on Bailm 104, 5 ; 1 Bouv. Inst. n. 1024.
     3. Special bail are discharged when the defendant dies, Tidd, 243 ;
actus Dei nemini facit injuriam being a maxim of law, applicable in such
case; but if the defendant die after the return of the case and before it is
filed, the bail are fixed. 6 T. R. 284; 6 Binn. 332, 338. It is, however, no
ground for an exonerator, that the defendant has become deranged since the
suit was brought, and is confined in a hospital. 2 Wash. C. C. R. 464, 6 T.
It. 133 Bos. & Pull. 362 Tidd, 184. Vide 8 Mass. Rep. 264; 3 Yeates, 37; 2
Dall. 317; 16 Mass. Rep. 218; Stra. 128; 1 Leigh's N, P. 508; 11 Pick. R.
41; 2 Verm. R. 92; 2 Watt's Rep. 443. See generally, Fortuitous Event;
Perils of the Sea.