Source : Webster's Revised Unabridged Dictionary (1913)

Hence \Hence\, adv. [OE. hennes, hens (the s is prop. a genitive
   ending; cf. {-wards}), also hen, henne, hennen, heonnen,
   heonene, AS. heonan, heonon, heona, hine; akin to OHG.
   hinn[=a]n, G. hinnen, OHG. hina, G. hin; all from the root of
   E. he. See {He}.]
   1. From this place; away. ``Or that we hence wend.''
      --Chaucer.

            Arise, let us go hence.               --John xiv.
                                                  31.

            I will send thee far hence unto the Gentiles. --Acts
                                                  xxii. 21.

   2. From this time; in the future; as, a week hence. ``Half an
      hour hence.'' --Shak.

Hence \Hence\, v. t.
   To send away. [Obs.] --Sir P. Sidney.

Source : WordNet®

hence
     adv 1: (used to introduce a logical conclusion) from that fact or
            reason or as a result; "therefore X must be true";
            "the eggs were fresh and hence satisfactory"; "we were
            young and thence optimistic"; "it is late and thus we
            must go"; "the witness is biased and so cannot be
            trusted" [syn: {therefore}, {thence}, {thus}]
     2: from this place; "get thee hence!"
     3: from this time; "a year hence it will be forgotten"