The Collaborative International Dictionary of English v.0.48:

Admonish \Ad*mon"ish\, v. t. [imp. & p. p. Admonished; p. pr.
   & vb. n. Admonishing.] [OE. amonesten, OF. amonester, F.
   admonester, fr. a supposed LL. admonesstrare, fr. L. admonere
   to remind, warn; ad + monere to warn. See Monition.]
   1. To warn or notify of a fault; to reprove gently or kindly,
      but seriously; to exhort. "Admonish him as a brother." --2
      Thess. iii. 15.
      [1913 Webster]

   2. To counsel against wrong practices; to cation or advise;
      to warn against danger or an offense; -- followed by of,
      against, or a subordinate clause.
      [1913 Webster]

            Admonishing one another in psalms and hymns. --Col.
                                                  iii. 16.
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            I warned thee, I admonished thee, foretold
            The danger, and the lurking enemy.    --Milton.
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   3. To instruct or direct; to inform; to notify.
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            Moses was admonished of God, when he was about to
            make the tabernacle.                  --Heb. viii.
                                                  5.
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The Collaborative International Dictionary of English v.0.48:

admonishing \admonishing\ adj.
   1. expressing adverse criticism as a corrective

   Syn: admonitory, reproachful, reproving
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

admonishing
    adj 1: expressing reproof or reproach especially as a corrective
           [syn: admonitory, admonishing, reproachful,
           reproving]