Source : Webster's Revised Unabridged Dictionary (1913)

Thence \Thence\, adv. [OE. thenne, thanne, and (with the
   adverbal -s; see {-wards}) thennes, thannes (hence thens, now
   written thence), AS. [eth]anon, [eth]anan, [eth]onan; akin to
   OHG. dannana, dann[=a]n, dan[=a]n, and G. von dannen, E.
   that, there. See {That}.]
   1. From that place. ``Bid him thence go.'' --Chaucer.

            When ye depart thence, shake off the dust under your
            feet for a testimony against them.    --Mark vi. 11.

   Note: It is not unusual, though pleonastic, to use from
         before thence. Cf. {Hence}, {Whence}.

               Then I will send, and fetch thee from thence.
                                                  --Gen. xxvii.
                                                  45.

   2. From that time; thenceforth; thereafter.

            There shall be no more thence an infant of days.
                                                  --Isa. lxv.
                                                  20.

   3. For that reason; therefore.

            Not to sit idle with so great a gift Useless, and
            thence ridiculous, about him.         --Milton.

   4. Not there; elsewhere; absent. [Poetic] --Shak.

Source : WordNet®

thence
     adv 1: from that place or from there; "proceeded thence directly to
            college"; "flew to Helsinki and thence to Moscow";
            "roads that lead therefrom" [syn: {therefrom}]
     2: from that circumstance or source; "atomic formulas and all
        compounds thence constructible"- W.V.Quine; "a natural
        conclusion follows thence"; "public interest and a policy
        deriving therefrom"; "typhus fever results therefrom"
        [syn: {therefrom}, {thereof}]
     3: (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},
         {hence}, {thus}]