primary

A primary election; a preliminary election to select a political candidate of a political party.

The first year of grade school.

A base or fundamental component; something that is irreducible.

The most massive component of a gravitationally bound system, such as a planet in relation to its satellites.

A primary school.

Any flight feather attached to the manus (hand) of a bird.

A primary colour.

Primary site of disease; original location or source of the disease.

“most common primaries”

A directly driven inductive coil, as in a transformer or induction motor that is magnetically coupled to a secondary

To challenge (an incumbent sitting politician) for their political party's endorsement to run for re-election, through running a challenger campaign in a primary election, especially one that is more ideologically extreme.

To take part in a primary election.

First or earliest in a group or series.

“Children attend primary school, and teenagers attend secondary school.”

Main; principal; chief; placed ahead of others.

“Preferred stock has primary claim on dividends, ahead of common stock.”

Earliest formed; fundamental.

Illustrating, possessing, or characterized by, some quality or property in the first degree; having undergone the first stage of substitution or replacement.

Relating to the place where a disorder or disease started to occur.

Relating to day-to-day care provided by health professionals such as nurses, general practitioners, dentists etc.