royal tennis vs real tennis

royal tennis and real tennis both are nouns.

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

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

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

Other synonyms of royal tennis include court tennis.

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