secondary vs indirect

secondary is a noun but indirect is not a noun.

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

secondary (noun)	indirect (noun)
coil such that current is induced in it by passing a current through the primary coil
the defensive football players who line up behind the linemen

secondary (adjective)	indirect (adjective)
being of second rank or importance or value; not direct or immediate	not direct in spatial dimension; not leading by a straight line or course to a destination
depending on or incidental to what is original or primary	extended senses; not direct in manner or language or behavior or action
inferior in rank or status	descended from a common ancestor but through different lines
not of major importance	having intervening factors or persons or influences
belonging to a lower class or rank	not as a direct effect or consequence