Secondary

Secondary is an adjective meaning "second" or "second hand". It may refer to:
 * Secondary education
 * A secondary consumer in an ecological sense.
 * A Secondary dominant in music.
 * The Secondary in American football and Canadian football refers to the group of (usually at least four) defensive backs.
 * A Secondary functional group (or usually ion) attached to carbon atom connected to 2 other Carbon atoms in organic chemistry
 * Secondaries, the second-largest group of remiges (wing feathers), which attach to the inner lower arm.
 * secondary circuit, electrical circuit in a Transformer in which current is produced by electromagnetic induction, as opposed to a primary circuit.