The Collaborative International Dictionary of English v.0.48:

Umbrage \Um"brage\ ([u^]m"br[asl]j; 48), n. [F. ombrage shade,
   suspicion, umbrage, L. umbraticus belonging to shade, fr.
   umbra a shade. Cf. Umber, Umbratic.]
   1. Shade; shadow; obscurity; hence, that which affords a
      shade, as a screen of trees or foliage.
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            Where highest woods, impenetrable
            To star or sunlight, spread their umbrage broad.
                                                  --Milton.
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   2. Shadowy resemblance; shadow. [Obs.]
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            The opinion carries no show of truth nor umbrage of
            reason on its side.                   --Woodward.
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   3. The feeling of being overshadowed; jealousy of another, as
      standing in one's light or way; hence, suspicion of injury
      or wrong; offense; resentment.
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            Which gave umbrage to wiser than myself. --Evelyn.
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            Persons who feel most umbrage from the overshadowing
            aristocracy.                          --Sir W.
                                                  Scott.
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WordNet (r) 3.0 (2006):

umbrage
    n 1: a feeling of anger caused by being offended; "he took
         offence at my question" [syn: umbrage, offense,
         offence]