estate car vs station waggon

estate car and station waggon both are nouns.

Word	Noun	Adjective	Verb	Adverb
estate car	Yes	No	No	No
station waggon	Yes	No	No	No

As nouns, estate car and station waggon are synonyms defined as:

estate car and station waggon: a car that has a long body and rear door with space behind rear seat

Other synonyms of estate car include beach waggon, beach wagon, station wagon, waggon, wagon.

estate car (noun)	station waggon (noun)
a car that has a long body and rear door with space behind rear seat	a car that has a long body and rear door with space behind rear seat