The Collaborative International Dictionary of English v.0.48:

caesura \cae*su"ra\, n.; pl. E. caesuras, L. C[ae]sur[ae]
   [L. caesura a cutting off, a division, stop, fr. caedere,
   caesum, to cut off. See Concise.]
   A metrical break in a verse, occurring in the middle of a
   foot and commonly near the middle of the verse; a sense pause
   in the middle of a foot. Also, a long syllable on which the
   c[ae]sural accent rests, or which is used as a foot.
   [1913 Webster]

   Note: In the following line the c[ae]sura is between study
         and of.
         [1913 Webster]

               The prop | er stud | y of | mankind | is man.
         [1913 Webster]

   2. a pause or interruption (as in a conversation); as, after
      an ominous caesura the preacher continued.
      [WordNet 1.5]