Meaning of PRIMARY in English
1》 of chief importance; principal.
2》 earliest in time or order.
↘( Primary ) Geology former term for Palaeozoic .
3》 not caused by or based on anything else.
4》 chiefly Brit. relating to or denoting education for children between the ages of about five and eleven.
5》 of or denoting the input side of a transformer or other inductive device.
6》 Chemistry (of an organic compound) having its functional group on a carbon atom bonded to no more than one other carbon atom.
↘derived from ammonia by replacement of one hydrogen atom by an organic group.
■ noun ( plural primaries )
1》 (in the US) a preliminary election to appoint delegates to a party conference or to select the candidates for a principal, especially presidential, election.
2》 Astronomy the body orbited by a smaller body.
ME: from L. primarius , from primus 'first'.
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004