The Collaborative International Dictionary of English v.0.48:

Rosary \Ro"sa*ry\, n.; pl. Rosaries. [LL. rosarium a string of
   beads, L. rosarium a place planted with roses, rosa a rose:
   cf. F. rosaire. See Rose.]
   1. A bed of roses, or place where roses grow. "Thick rosaries
      of scented thorn." --Tennyson.
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   2. (R.C.Ch.) A series of prayers (see Note below) arranged to
      be recited in order, on beads; also, a string of beads by
      which the prayers are counted.
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            His idolized book, and the whole rosary of his
            prayers.                              --Milton.
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   Note: A rosary consists of fifteen decades. Each decade
         contains ten Ave Marias marked by small beads, preceded
         by a Paternoster, marked by a larger bead, and
         concluded by a Gloria Patri. Five decades make a
         chaplet, a third part of the rosary. --Bp. Fitzpatrick.
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   3. A chapelet; a garland; a series or collection, as of
      beautiful thoughts or of literary selections.
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            Every day propound to yourself a rosary or chaplet
            of good works to present to God at night. --Jer.
                                                  Taylor.
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   4. A coin bearing the figure of a rose, fraudulently
      circulated in Ireland in the 13th century for a penny.
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   Rosary shell (Zool.), any marine gastropod shell of the
      genus Monodonta. They are top-shaped, bright-colored and
      pearly.
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