Source : Webster's Revised Unabridged Dictionary (1913)

Scot \Scot\, n. [Icel. skot; or OF. escot, F. ['e]cot, LL.
   scottum, scotum, from a kindred German word; akin to AS.
   scot, and E. shot, shoot; cf. AS. sce['o]tan to shoot, to
   contribute. See {Shoot}, and cf. {Shot}.]
   A portion of money assessed or paid; a tax or contribution; a
   mulct; a fine; a shot.

   {Scot and lot}, formerly, a parish assessment laid on
      subjects according to their ability. [Eng.] --Cowell. Now,
      a phrase for obligations of every kind regarded
      collectivelly.

            Experienced men of the world know very well that it
            is best to pay scot and lot as they go along.
                                                  --Emerson.

Source : WordNet®

scot and lot
     n : obligations of all kinds taken as a whole