Source : Webster's Revised Unabridged Dictionary (1913)

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.

            Then would unbalanced heat licentious reign, Crack
            the dry hill, and chap the russet plain.
                                                  --Blackmore.

            Nor winter's blast chap her fair face. --Lyly.

   2. To strike; to beat. [Scot.]

Source : WordNet®

chapping
     See {chap}

chap
     v : crack due to dehydration; "My lips chap in this dry weather"
     [also: {chapping}, {chapped}]

chap
     n 1: a boy or man; "that chap is your host"; "there's a fellow at
          the door"; "he's a likable cuss" [syn: {fellow}, {feller},
           {lad}, {gent}, {fella}, {blighter}, {cuss}]
     2: a long narrow depression in a surface [syn: {crevice}, {cranny},
         {crack}, {fissure}]
     3: a crack in a lip caused usually by cold
     4: (usually in the plural) leather leggings without a seat;
        joined by a belt; often have flared outer flaps; worn over
        trousers by cowboys to protect their legs
     [also: {chapping}, {chapped}]