Source : Webster's Revised Unabridged Dictionary (1913)

Along \A*long"\ [AS. gelang owing to.]
   (Now heard only in the prep. phrase along of.)

   {Along of}, {Along on}, often shortened to {Long of}, prep.
      phr., owing to; on account of. [Obs. or Low. Eng.] ``On me
      is not along thin evil fare.'' --Chaucer. ``And all this
      is long of you.'' --Shak. ``This increase of price is all
      along of the foreigners.'' --London Punch.

Along \A*long"\ (?; 115), adv. [OE. along, anlong, AS. andlang,
   along; pref. and- (akin to OFris. ond-, OHG. ant-, Ger. ent-,
   Goth. and-, anda-, L. ante, Gr. ?, Skr. anti, over against) +
   lang long. See {Long}.]
   1. By the length; in a line with the length; lengthwise.

            Some laid along . . . on spokes of wheels are hung.
                                                  --Dryden.

   2. In a line, or with a progressive motion; onward; forward.

            We will go along by the king's highway. --Numb. xxi.
                                                  22.

            He struck with his o'ertaking wings, And chased us
            south along.                          --Coleridge.

   3. In company; together.

            He to England shall along with you.   --Shak.

   {All along}, all through the course of; during the whole
      time; throughout. ``I have all along declared this to be a
      neutral paper.'' --Addison.

   {To get along}, to get on; to make progress, as in business.
      ``She 'll get along in heaven better than you or I.''
      --Mrs. Stowe.

Along \A*long"\, prep.
   By the length of, as distinguished from across. ``Along the
   lowly lands.'' --Dryden.

         The kine . . . went along the highway.   --1 Sam. vi.
                                                  12.

Source : WordNet®

along
     adv 1: with a forward motion; "we drove along admiring the view";
            "the horse trotted along at a steady pace"; "the
            circus traveled on to the next city"; "move along";
            "march on" [syn: {on}]
     2: in accompaniment or as a companion; "his little sister came
        along to the movies"; "I brought my camera along";
        "working along with his father"
     3: to a more advanced state; "the work is moving along"; "well
        along in their research"; "hurrying their education
        along"; "getting along in years"
     4: in addition (usually followed by `with'); "we sent them food
        and some clothing went along in the package"; "along with
        the package came a bill"; "consider the advantages along
        with the disadvantages"
     5: in line with a length or direction (often followed by `by'
        or `beside'); "pass the word along"; "ran along beside
        me"; "cottages along by the river"