As an adjective, it means main or most important, or relating to the first stage of education. As a noun, it can refer to an early election to choose a party’s candidate.
From Latin *primarius* meaning 'of the first rank', from *primus* 'first'. It came through Middle French into English with the sense of being first in order or importance.
‘Primary’ is the language version of 'Player One'—first in line, first in importance. Primary colors in art, primary school in education, primary sources in research: the word keeps marking the starting blocks. Once you spot it, you can see how systems quietly label what counts as 'most basic'.
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