court tennis vs royal tennis

court tennis and royal tennis both are nouns.

Word	Noun	Adjective	Verb	Adverb
court tennis	Yes	No	No	No
royal tennis	Yes	No	No	No

As nouns, court tennis and royal tennis are synonyms defined as:

court tennis and royal tennis: an ancient form of tennis played in a four-walled court

Other synonyms of court tennis include real tennis.

court tennis (noun)	royal tennis (noun)
an ancient form of tennis played in a four-walled court	an ancient form of tennis played in a four-walled court