password vs watchword

password and watchword both are nouns.

Word	Noun	Adjective	Verb	Adverb
password	Yes	No	No	No
watchword	Yes	No	No	No

As nouns, password and watchword are synonyms defined as:

password and watchword: a secret word or phrase known only to a restricted group

Other synonyms of password include countersign, parole, word.

password (noun)	watchword (noun)
a secret word or phrase known only to a restricted group	a secret word or phrase known only to a restricted group
	a slogan used to rally support for a cause