dishwasher vs dish washer

dishwasher and dish washer both are nouns.

Word	Noun	Adjective	Verb	Adverb
dishwasher	Yes	No	No	No
dish washer	Yes	No	No	No

As nouns, dishwasher and dish washer are synonyms defined as:

Other synonyms of dishwasher include dishwashing machine.

dishwasher (noun)	dish washer (noun)
a machine for washing dishes	a machine for washing dishes
someone who washes dishes