Source : Webster's Revised Unabridged Dictionary (1913)

Beside \Be*side"\, prep. [OE. biside, bisiden, bisides, prep.
   and adv., beside, besides; pref. be- by + side. Cf. Besides,
   and see {Side}, n.]
   1. At the side of; on one side of. ``Beside him hung his
      bow.'' --Milton.

   2. Aside from; out of the regular course or order of; in a
      state of deviation from; out of.

            [You] have done enough To put him quite beside his
            patience.                             --Shak.

   3. Over and above; distinct from; in addition to.

   Note: [In this use besides is now commoner.]

               Wise and learned men beside those whose names are
               in the Christian records.          --Addison.

   {To be beside one's self}, to be out of one's wits or senses.

            Paul, thou art beside thyself.        --Acts xxvi.
                                                  24.

   Syn: {Beside}, {Besides}.

   Usage: These words, whether used as prepositions or adverbs,
          have been considered strictly synonymous, from an
          early period of our literature, and have been freely
          interchanged by our best writers. There is, however, a
          tendency, in present usage, to make the following
          distinction between them: 1. That beside be used only
          and always as a preposition, with the original meaning
          ``by the side of; '' as, to sit beside a fountain; or
          with the closely allied meaning ``aside from'',
          ``apart from'', or ``out of''; as, this is beside our
          present purpose; to be beside one's self with joy. The
          adverbial sense to be wholly transferred to the
          cognate word. 2. That besides, as a preposition, take
          the remaining sense ``in addition to'', as, besides
          all this; besides the considerations here offered.
          ``There was a famine in the land besides the first
          famine.'' --Gen. xxvi. 1. And that it also take the
          adverbial sense of ``moreover'', ``beyond'', etc.,
          which had been divided between the words; as, besides,
          there are other considerations which belong to this
          case. The following passages may serve to illustrate
          this use of the words:

                Lovely Thais sits beside thee.    --Dryden.

                Only be patient till we have appeased The
                multitude, beside themselves with fear. --Shak.

                It is beside my present business to enlarge on
                this speculation.                 --Locke.

                Besides this, there are persons in certain
                situations who are expected to be charitable.
                                                  --Bp. Porteus.

                And, besides, the Moor May unfold me to him;
                there stand I in much peril.      --Shak.

                That man that does not know those things which
                are of necessity for him to know is but an
                ignorant man, whatever he may know besides.
                                                  --Tillotson.

   Note: See {Moreover}.