The Collaborative International Dictionary of English v.0.48:

Chap \Chap\ (ch[a^]p or ch[o^]p), v. t. [imp. & p. p. Chapped
   (ch[a^]pt or ch[o^]pt); p. pr. & vb. n. Chapping.] [See
   Chop to cut.]
   1. To cause to open in slits or chinks; to split; to cause
      the skin of to crack or become rough.
      [1913 Webster]

            Then would unbalanced heat licentious reign,
            Crack the dry hill, and chap the russet plain.
                                                  --Blackmore.
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            Nor winter's blast chap her fair face. --Lyly.
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   2. To strike; to beat. [Scot.]
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WordNet (r) 3.0 (2006):

chapped
    adj 1: used of skin roughened as a result of cold or exposure;
           "chapped lips" [syn: chapped, cracked, roughened]