secondary vs standby

secondary and standby both are nouns.

Word	Noun	Adjective	Verb	Adverb
secondary	Yes	Yes	No	No
standby	Yes	Yes	No	No

secondary (noun)	standby (noun)
coil such that current is induced in it by passing a current through the primary coil	something that can be relied on when needed
the defensive football players who line up behind the linemen	an actor able to replace a regular performer when required

secondary (adjective)	standby (adjective)
being of second rank or importance or value; not direct or immediate	ready for emergency use
depending on or incidental to what is original or primary
inferior in rank or status
not of major importance
belonging to a lower class or rank