primary

A preliminary election where delegates or nominees are chosen.

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”

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

Of or being the essential or basic part.

Most important element.

“policemen were primary targets”

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”

“a primary effect”