secondary (the usual work)

extra; supplementary

giving additional help or support

supplementary

secondary or subordinate but from the same source

indirect, secondary

an organic chemical substance formed in plants and animals, able to cause chemical changes without being changed itself

something which incites activity

(a person who is) lower in rank or position; to consider or treat (a person, one's own wishes) as less important

lesser, supplementary

(a person, business etc) not as important, high in position etc as the main person, business etc

secondary, helpful