This is the 11074th most frequent Spanish word.
eclesiásticas
"Ecclesiastical" – relating to the church or clergy.
In this sentence, 'eclesiásticas' is an adjective describing 'authorities', indicating that they are related to the church or clerical matters.
Las autoridades eclesiásticas decidieron restaurar la iglesia este año.
The ecclesiastical authorities decided to restore the church this year.
Here, 'eclesiástica' qualifies 'música', indicating that the music pertains to the church traditions or ecclesiastical context.
La música eclesiástica tiene un tono solemne que inspira reverencia.
The ecclesiastical music has a solemn tone that inspires reverence.
In this context, 'eclesiásticas' modifies 'construcciones', referring to buildings that were meant for church use or worship.