Definition of "Primary" :

noun: a preliminary election where delegates or nominees are chosen

noun: one of the main flight feathers projecting along the outer edge of a bird's wing

noun: coil forming the part of an electrical circuit such that changing current in it induces a current in a neighboring circuit

"Current through the primary coil induces current in the secondary coil."

noun: (astronomy) a celestial body (especially a star) relative to other objects in orbit around it

adjective: not derived from or reducible to something else; basic

"A primary instinct."

adjective: most important element

"Policemen were primary targets."

adjective: of first rank or importance or value; direct and immediate rather than secondary

"Primary goals."

adjective: of or being the essential or basic part