Source : Webster's Revised Unabridged Dictionary (1913)

Out \Out\, adv. [OE. out, ut, oute, ute, AS. [=u]t, and [=u]te,
   [=u]tan, fr. [=u]t; akin to D. uit, OS. [=u]t, G. aus, OHG.
   [=u]z, Icel. [=u]t, Sw. ut, Dan. ud, Goth. ut, Skr. ud.
   [root]198. Cf. {About}, {But}, prep., {Carouse}, {Utter}, a.]
   In its original and strict sense, out means from the interior
   of something; beyond the limits or boundary of somethings; in
   a position or relation which is exterior to something; --
   opposed to {in} or {into}. The something may be expressed
   after of, from, etc. (see {Out of}, below); or, if not
   expressed, it is implied; as, he is out; or, he is out of the
   house, office, business, etc.; he came out; or, he came out
   from the ship, meeting, sect, party, etc. Out is used in a
   variety of applications, as:

   1. Away; abroad; off; from home, or from a certain, or a
      usual, place; not in; not in a particular, or a usual,
      place; as, the proprietor is out, his team was taken out.
      ``My shoulder blade is out.'' --Shak.

            He hath been out (of the country) nine years.
                                                  --Shak.

   2. Beyond the limits of concealment, confinement, privacy,
      constraint, etc., actual of figurative; hence, not in
      concealment, constraint, etc., in, or into, a state of
      freedom, openness, disclosure, publicity, etc.; as, the
      sun shines out; he laughed out, to be out at the elbows;
      the secret has leaked out, or is out; the disease broke
      out on his face; the book is out.

            Leaves are out and perfect in a month. --Bacon.

            She has not been out [in general society] very long.
                                                  --H. James.

   3. Beyond the limit of existence, continuance, or supply; to
      the end; completely; hence, in, or into, a condition of
      extinction, exhaustion, completion; as, the fuel, or the
      fire, has burned out. ``Hear me out.'' --Dryden.

            Deceitiful men shall not live out half their days.
                                                  --Ps. iv. 23.

            When the butt is out, we will drink water. --Shak.

   4. Beyond possession, control, or occupation; hence, in, or
      into, a state of want, loss, or deprivation; -- used of
      office, business, property, knowledge, etc.; as, the
      Democrats went out and the Whigs came in; he put his money
      out at interest. ``Land that is out at rack rent.''
      --Locke. ``He was out fifty pounds.'' --Bp. Fell.

            I have forgot my part, and I am out.  --Shak.

   5. Beyond the bounds of what is true, reasonable, correct,
      proper, common, etc.; in error or mistake; in a wrong or
      incorrect position or opinion; in a state of disagreement,
      opposition, etc.; in an inharmonious relation. ``Lancelot
      and I are out.'' --Shak.

            Wicked men are strangely out in the calculating of
            their own interest.                   --South.

            Very seldom out, in these his guesses. --Addison.

   6. Not in the position to score in playing a game; not in the
      state or turn of the play for counting or gaining scores.

   Note: Out is largely used in composition as a prefix, with
         the same significations that it has as a separate word;
         as outbound, outbreak, outbuilding, outcome, outdo,
         outdoor, outfield. See also the first Note under
         {Over}, adv.

   {Day in, day out}, from the beginning to the limit of each of
      several days; day by day; every day.

   {Out and out}.
      (a) adv. Completely; wholly; openly.
      (b) adj. Without any reservation or disguise; absolute;
          as, an out and out villain. [As an {adj}. written also
          {out-and-out}.]

   {Out at}, {Out in}, {Out on}, etc., elliptical phrases, that
      to which out refers as a source, origin, etc., being
      omitted; as, out (of the house and) at the barn; out (of
      the house, road, fields, etc., and) in the woods.

            Three fishers went sailing out into the west, Out
            into the west, as the sun went down.  --C. Kingsley.

   Note: In these lines after out may be understood, ``of the
         harbor,'' ``from the shore,'' ``of sight,'' or some
         similar phrase. The complete construction is seen in
         the saying: ``Out of the frying pan into the fire.''

   {Out from}, a construction similar to {out of} (below). See
      {Of} and {From}.

   {Out of}, a phrase which may be considered either as composed
      of an adverb and a preposition, each having its
      appropriate office in the sentence, or as a compound
      preposition. Considered as a preposition, it denotes, with
      verbs of movement or action, from the interior of; beyond
      the limit: from; hence, origin, source, motive, departure,
      separation, loss, etc.; -- opposed to {in} or {into}; also
      with verbs of being, the state of being derived, removed,
      or separated from. Examples may be found in the phrases
      below, and also under Vocabulary words; as, out of breath;
      out of countenance.

   {Out of cess}, beyond measure, excessively. --Shak.

   {Out of character}, unbecoming; improper.

   {Out of conceit with}, not pleased with. See under {Conceit}.
      

   {Out of date}, not timely; unfashionable; antiquated.

   {Out of door}, {Out of doors}, beyond the doors; from the
      house; in, or into, the open air; hence, figuratively,
      shut out; dismissed. See under {Door}, also,
      {Out-of-door}, {Outdoor}, {Outdoors}, in the Vocabulary.
      ``He 's quality, and the question's out of door,''
      --Dryden.

   {Out of favor}, disliked; under displeasure.

   {Out of frame}, not in correct order or condition; irregular;
      disarranged. --Latimer.

   {Out of hand}, immediately; without delay or preparation.
      ``Ananias . . . fell down and died out of hand.''
      --Latimer.

Source : WordNet®

day in day out
     adv : for an indefinite number of successive days [syn: {day after
           day}]