primary

a preliminary election where delegates or nominees are chosen

of or being the essential or basic part

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

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”

most important element

“policemen were primary targets”

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

not derived from or reducible to something else; basic

“a primary instinct”

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

“primary goals”