primary

/ˈprī-ˌmer-ē/

Middle English primarye, primary "original, earliest," borrowed from Latin prīmārius "of the highest importance or station (of persons), first-rate, chief" (Late Latin, "original, lying at the beginning," Medieval Latin, "foremost, leading"), from prīmus "first, foremost, earliest, of first importance" + -ārius

adjective

first in order of time or development : primitive
of first rank, importance, or value : principal
basic, fundamental

the primary stage of civilization

noun

something that stands first in rank, importance, or value : fundamental —usually used in plural
the celestial body around which one or more other celestial bodies revolve; especially : the more massive usually brighter component of a binary star system
one of the usually 9 or 10 strong flight feathers on the distal joint of a bird's wing

verb

to run against (an incumbent) in a primary election —usually used in the passive

She won the seat in 2020 after successfully primarying a veteran Democrat in the district.