japan clover vs jap clover

japan clover and jap clover both are nouns.

Word	Noun	Adjective	Verb	Adverb
japan clover	Yes	No	No	No
jap clover	Yes	No	No	No

As nouns, japan clover and jap clover are synonyms defined as:

japan clover and jap clover: an annual of tropical Asia naturalized in United States

Other synonyms of japan clover include japanese clover, Lespedeza striata.

japan clover (noun)	jap clover (noun)
an annual of tropical Asia naturalized in United States	an annual of tropical Asia naturalized in United States