Source : Webster's Revised Unabridged Dictionary (1913)

Psalter \Psal"ter\, n. [OE. psauter, sauter, OF. sautier,
   psaltier, F. psautier, from L. psalterium. See {Psaltery}.]
   1. The Book of Psalms; -- often applied to a book containing
      the Psalms separately printed.

   2. Specifically, the Book of Psalms as printed in the Book of
      Common Prayer; among the Roman Catholics, the part of the
      Breviary which contains the Psalms arranged for each day
      of the week.

   3. (R. C. Ch.) A rosary, consisting of a hundred and fifty
      beads, corresponding to the number of the psalms.

Source : WordNet®

Psalter
     n : a collection of Psalms for liturgical use [syn: {Book of
         Psalms}]