alliance vs silver cord

alliance and silver cord both are nouns.

Word	Noun	Adjective	Verb	Adverb
alliance	Yes	No	No	No
silver cord	Yes	No	No	No

As nouns, silver cord is a hyponym of alliance; that is, silver cord is a word with a more specific, narrower meaning than alliance:

alliance (noun)	silver cord (noun)
the act of forming an alliance or confederation	the emotional bond between a mother and her offspring
a formal agreement establishing an association or alliance between nations or other groups to achieve a particular aim
an organization of people (or countries) involved in a pact or treaty
a connection based on kinship or marriage or common interest
the state of being allied or confederated