orthopter vs ornithopter

orthopter and ornithopter both are nouns.

Word	Noun	Adjective	Verb	Adverb
orthopter	Yes	No	No	No
ornithopter	Yes	No	No	No

As nouns, orthopter and ornithopter are synonyms defined as:

orthopter and ornithopter: heavier-than-air craft that is propelled by the flapping of wings

orthopter (noun)	ornithopter (noun)
heavier-than-air craft that is propelled by the flapping of wings	heavier-than-air craft that is propelled by the flapping of wings