kymograph vs cymograph

kymograph and cymograph both are nouns.

Word	Noun	Adjective	Verb	Adverb
kymograph	Yes	No	No	No
cymograph	Yes	No	No	No

As nouns, kymograph and cymograph are synonyms defined as:

kymograph and cymograph: scientific instrument consisting of a rotating drum holding paper on which a stylus traces a continuous record (as of breathing or blood pressure)

kymograph (noun)	cymograph (noun)
scientific instrument consisting of a rotating drum holding paper on which a stylus traces a continuous record (as of breathing or blood pressure)	scientific instrument consisting of a rotating drum holding paper on which a stylus traces a continuous record (as of breathing or blood pressure)