land rail vs Crex crex

land rail and Crex crex both are nouns.

Word	Noun	Adjective	Verb	Adverb
land rail	Yes	No	No	No
Crex crex	Yes	No	No	No

As nouns, land rail and Crex crex are synonyms defined as:

land rail and Crex crex: common Eurasian rail that frequents grain fields

Other synonyms of land rail include corncrake.

land rail (noun)	Crex crex (noun)
common Eurasian rail that frequents grain fields	common Eurasian rail that frequents grain fields