house of worship vs house of prayer

house of worship and house of prayer both are nouns.

Word	Noun	Adjective	Verb	Adverb
house of worship	Yes	No	No	No
house of prayer	Yes	No	No	No

As nouns, house of worship and house of prayer are synonyms defined as:

house of worship and house of prayer: any building where congregations gather for prayer

Other synonyms of house of worship include house of God, place of worship.

house of worship (noun)	house of prayer (noun)
any building where congregations gather for prayer	any building where congregations gather for prayer