The Collaborative International Dictionary of English v.0.48:

frank \frank\ (fr[a^][ng]k), a. [Compar. franker
   (fr[a^][ng]k"[~e]r); superl. frankest.] [F. franc free,
   frank, L. Francus a Frank, fr. OHG. Franko the name of a
   Germanic people on the Rhine, who afterward founded the
   French monarchy; cf. AS. franca javelin, Icel. frakka. Cf.
   Franc, French, a., Franchise, n.]
   1. Unbounded by restrictions, limitations, etc.; free. [R.]
      "It is of frank gift." --Spenser.
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   2. Free in uttering one's real sentiments; not reserved;
      using no disguise; candid; ingenuous; as, a frank nature,
      conversation, manner, etc.
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   3. Liberal; generous; profuse. [Obs.]
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            Frank of civilities that cost them nothing.
                                                  --L'Estrange.
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   4. Unrestrained; loose; licentious; -- used in a bad sense.
      --Spenser.

   Syn: Ingenuous; candid; artless; plain; open; unreserved;
        undisguised; sincere. See Candid, Ingenuous.
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