What is the meaning of Conservatory?

Having the quality of preserving from loss, decay, or injury.

Relating to conservation.

A medicine, especially a magical preservative.

A school or clinic for orphans.

A music school.

A storehouse, a repository.

An icehouse, a warehouse for ice.

A cistern, an artificially collected body of water.

A reservoir, an artificially maintained body of water.

A greenhouse, a glass-walled building for cultivating delicate plants.

A solarium, a glass-walled and glass-roofed room in a house.

A drama school. (Can we verify this sense?)

Source: wiktionary.org