noun
- A primary school.
- A directly driven inductive coil, as in a transformer or induction motor that is magnetically coupled to a secondary
- A primary election; a preliminary election to select a political candidate of a political party.
- A radar return from an aircraft (or other object) produced solely by the reflection of the radar beam from the aircraft's skin, without additional information from the aircraft's transponder.
- Any flight feather attached to the manus (hand) of a bird.
- 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.
- The first year of grade school.
- A primary colour.
- Primary site of disease; original location or source of the disease.
- The first stage of a thermonuclear weapon, which sets off a fission explosion to help trigger a fusion reaction in the weapon's secondary stage.
verb
- To challenge (an incumbent sitting politician) for their political party's nomination 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.
adj
- Earliest formed; fundamental.
- first or earliest in a group or series.
- main; principal; chief; placed ahead of others.
- Relating to day-to-day care provided by health professionals such as nurses, general practitioners, dentists etc.
- Relating to the place where a disorder or disease started to occur.
- Illustrating, possessing, or characterized by, some quality or property in the first degree; having undergone the first stage of substitution or replacement.