The Collaborative International Dictionary of English v.0.48:

Stanch \Stanch\ (st[.a]nch), v. t. [imp. & p. p. Stanched
   (st[.a]ncht); p. pr. & vb. n. Stanching.] [OF. estanchier,
   F. ['e]tancher to stop a liquid from flowing; akin to Pr.,
   Sp., & Pg. estancar, It. stancare to weary, LL. stancare,
   stagnare, to stanch, fr. L. stagnare to be or make stagnant.
   See Stagnate.]
   1. To stop the flowing of, as blood; to check; also, to stop
      the flowing of blood from; as, to stanch a wound. [Written
      also staunch.]
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            Iron or a stone laid to the neck doth stanch the
            bleeding of the nose.                 --Bacon.
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   2. To extinguish; to quench, as fire or thirst. [Obs.]
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The Collaborative International Dictionary of English v.0.48:

Stanch \Stanch\, a. [Compar. Stancher (-[~e]r); superl.
   Stanchest.] [From Stanch, v. t., and hence literally
   signifying, stopped or stayed; cf. Sp. estanco stopped,
   tight, not leaky, as a ship. See Stanch, v. t.] [Written
   also staunch.]
   1. Strong and tight; sound; firm; as, a stanch ship.
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            One of the closets is parqueted with plain deal, set
            in diamond, exceeding stanch and pretty. --Evelyn.
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   2. Firm in principle; constant and zealous; loyal; hearty;
      steady; steadfast; as, a stanch churchman; a stanch friend
      or adherent. --V. Knox.
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            In politics I hear you 're stanch.    --Prior.
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   3. Close; secret; private. [Obs.]
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            This is to be kept stanch.            --Locke.
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The Collaborative International Dictionary of English v.0.48:

Staunch \Staunch\ (st[aum]nch), Staunchly \Staunch"ly\,
Staunchness \Staunch"ness\, etc.
   See Stanch, Stanchly, etc.
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WordNet (r) 3.0 (2006):

staunch
    adj 1: firm and dependable especially in loyalty; "a steadfast
           ally"; "a staunch defender of free speech"; "unswerving
           devotion"; "unswerving allegiance" [syn: steadfast,
           staunch, unswerving]
    v 1: stop the flow of a liquid; "staunch the blood flow"; "stem
         the tide" [syn: stem, stanch, staunch, halt]