first or highest in rank or importance; chief; principal

his primary goals in life.

first in order in any series, sequence, etc.

first in time; earliest; primitive.

of, pertaining to, or characteristic of primary school

the primary grades.

constituting or belonging to the first stage in any process.

of the nature of the ultimate or simpler constituents of which something complex is made up

Animals have a few primary instincts.

original; not derived or subordinate; fundamental; basic.

immediate or direct, or not involving intermediate agency

primary perceptions.

Sociology . (of social values or ideals) conceived as derived from the primary group and culturally defined as being necessary to the welfare of the individual and society.

Ornithology . pertaining to any of the set of flight feathers situated on the distal segment of a bird's wing.

Electricity . noting or pertaining to the circuit, coil, winding, or current that induces current in secondary windings in an induction coil, transformer, or the like.

Chemistry .

involving or obtained by replacement of one atom or group.

noting or containing a carbon atom united to no other or to only one other carbon atom in a molecule.

Grammar .

(of a derivative) having a root or other unanalyzable element as the underlying form.

(of Latin, Greek, Sanskrit tenses) having reference to present or future time. Compare secondary ( def. 9 ) .

something that is first in order, rank, or importance.

U.S. Politics .

Also called primary election. a preliminary election in which voters of each party nominate candidates for office, party officers, etc. Compare closed primary , direct primary , indirect primary , open primary .

a meeting of the voters of a political party in an election district for nominating candidates for office, choosing delegates for a convention, etc.; caucus.

primary color.

Ornithology . a primary feather.

Electricity . a winding in a transformer or the like that carries a current and that induces a current in secondary windings.

Astronomy .

a body in relation to a smaller body or smaller bodies revolving around it, as a planet in relation to its satellites.

the brighter of the two stars comprising a double star. Compare companion 1 ( def. 6 ) .

adjective

capital , cardinal , chief , first , foremost , key , leading , main , major , number one , paramount , premier , prime , principal , top , earliest , initial , maiden , original , pioneer , primordial , primitive , basal , basic , foundational , fundamental , underlying , direct , firsthand , central , constitutional , dominant , elementary , essential , idiopathic , immediate , primal , simple , vital

noun

abecedarium , hornbook , primer