mid-15c., rosarie, "rose garden, ground set apart for the cultivation of roses," a sense now obsolete, from Latin rosarium "rose garden," in Medieval Latin also "garland; string of beads; series of prayers," from noun use of neuter of rosarius "of roses," from rosa "rose" (see rose (n.1)).
The sense of "series of prayers" is attested by 1540s, from French rosaire, a figurative use of the French word meaning "rose garden," on the notion of a "garden" of prayers. In high medieval times, collections often were compared to bouquets (compare anthology and Medieval Latin hortulus animae "prayerbook," literally "little garden of the soul"). The meaning was transferred by 1590s to the strings of beads carried on the person and used as a memory aid in reciting the rosary.
updated on September 29, 2021