speed skater vs speedskater

speed skater and speedskater both are nouns.

Word	Noun	Adjective	Verb	Adverb
speed skater	Yes	No	No	No
speedskater	Yes	No	No	No

As nouns, speed skater and speedskater are synonyms defined as:

speed skater and speedskater: an ice-skater who races competitively; usually around an oval course

speed skater (noun)	speedskater (noun)
an ice-skater who races competitively; usually around an oval course	an ice-skater who races competitively; usually around an oval course