swan-neck vs swan orchid

swan-neck and swan orchid both are nouns.

Word	Noun	Adjective	Verb	Adverb
swan-neck	Yes	No	No	No
swan orchid	Yes	No	No	No

As nouns, swan-neck and swan orchid are synonyms defined as:

swan-neck and swan orchid: any of several orchids of the genus Cycnoches having slender arching columns of flowers suggesting the neck of a swan

Other synonyms of swan-neck include swan-flower, swanflower, swanneck.

swan-neck (noun)	swan orchid (noun)
any of several orchids of the genus Cycnoches having slender arching columns of flowers suggesting the neck of a swan	any of several orchids of the genus Cycnoches having slender arching columns of flowers suggesting the neck of a swan