1coming after, less important than, or resulting from someone or something else that is primary:luck plays a role, but it’s ultimately secondary to local knowledge relating to education for children from the age of eleven to sixteen or eighteen:a secondary school having a reversible chemical reaction and therefore able to store energy: the lead-acid accumulator used in cars consists of secondary cells relating to or denoting the output side of a device using electromagnetic induction, especially in a transformer: the primary and secondary coils of the transformer 2 (Secondary) Geologyformer term for Mesozoic.
3 Chemistry (of an organic compound) having its functional group located on a carbon atom which is bonded to two other carbon atoms. (chiefly of amines) derived from ammonia by replacement of two hydrogen atoms by organic groups.
British a secondary school. Ornithology a secondary feather. a secondary coil or winding in an electrical transformer.
, dated the Secondary or Mesozoic era.