The Collaborative International Dictionary of English v.0.48:

Derive \De*rive"\, v. t. [imp. & p. p. Derived; p. pr. & vb.
   n. Deriving.] [F. d['e]river, L. derivare; de- + rivus
   stream, brook. See Rival.]
   1. To turn the course of, as water; to divert and distribute
      into subordinate channels; to diffuse; to communicate; to
      transmit; -- followed by to, into, on, upon. [Obs.]
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            For fear it [water] choke up the pits . . . they
            [the workman] derive it by other drains. --Holland.
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            Her due loves derived to that vile witch's share.
                                                  --Spenser.
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            Derived to us by tradition from Adam to Noah. --Jer.
                                                  Taylor.
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   2. To receive, as from a source or origin; to obtain by
      descent or by transmission; to draw; to deduce; --
      followed by from.
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   3. To trace the origin, descent, or derivation of; to
      recognize transmission of; as, he derives this word from
      the Anglo-Saxon.
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            From these two causes . . . an ancient set of
            physicians derived all diseases.      --Arbuthnot.
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   4. (Chem.) To obtain one substance from another by actual or
      theoretical substitution; as, to derive an organic acid
      from its corresponding hydrocarbon.

   Syn: To trace; deduce; infer.
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WordNet (r) 3.0 (2006):

deriving
    n 1: (historical linguistics) an explanation of the historical
         origins of a word or phrase [syn: deriving, derivation,
         etymologizing]