slave owner vs slaveholder

slave owner and slaveholder both are nouns.

Word	Noun	Adjective	Verb	Adverb
slave owner	Yes	No	No	No
slaveholder	Yes	No	No	No

As nouns, slave owner and slaveholder are synonyms defined as:

Other synonyms of slave owner include slaver.

slave owner (noun)	slaveholder (noun)
someone who holds slaves	someone who holds slaves