Definition of "Secondary" :

noun: coil such that current is induced in it by passing a current through the primary coil

noun: the defensive football players who line up behind the linemen

adjective: belonging to a lower class or rank

adjective: not of major importance

"Played a secondary role in world events."

adjective: being of second rank or importance or value; not direct or immediate

"The stone will be hauled to a secondary crusher."

adjective: depending on or incidental to what is original or primary

"A secondary infection."

adjective: inferior in rank or status