paddlewheel vs paddle wheel

paddlewheel and paddle wheel both are nouns.

Word	Noun	Adjective	Verb	Adverb
paddlewheel	Yes	No	No	No
paddle wheel	Yes	No	No	No

As nouns, paddlewheel and paddle wheel are synonyms defined as:

paddlewheel and paddle wheel: a large wheel fitted with paddles and driven by an engine in order to propel a boat

paddlewheel (noun)	paddle wheel (noun)
a large wheel fitted with paddles and driven by an engine in order to propel a boat	a large wheel fitted with paddles and driven by an engine in order to propel a boat