What is the meaning of Rosary?

Prayer beads, a string of beads used to keep track of repetitions in prayer, particularly in the Roman Catholic Marian prayer "Hail Mary" (Ave Maria)

A Roman Catholic devotion involving the repetition of a series of Marian prayers, usually 5, 15, or 20 decades of "Hail Marys", each decade beginning with "Our Father" and ending with "Glory Be to the Father", but sometimes including other Roman Catholic, Anglican, or Lutheran prayers.

A series or collection of thoughts, literary pieces, etc. intended for similar contemplation.

A 13th-century coin minted in Europe as a counterfeit debased form of the sterling silver penny of Edward I, at first accepted as a halfpenny and then outlawed.

A rose garden.

Source: wiktionary.org