Secondary may refer to:

Science and nature

Secondary emission In particle physics, secondary emission is a phenomenon where primary incident particles of sufficient energy, when hitting a surface or passing through some material, induce the emission of secondary particles. The term often refers to the emi ...

, of particles **

Secondary electrons Secondary electrons are electrons generated as ionization products. They are called 'secondary' because they are generated by other radiation (the ''primary'' radiation). This radiation can be in the form of ions, electrons, or photons with suffici ...

, electrons generated as ionization products * The secondary winding, or the electrical or electronic circuit connected to the secondary winding in a

transformer A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer' ...

* Secondary (chemistry), a term used in organic chemistry to classify various types of compounds *

Secondary color A secondary color is a color made by color mixing, mixing of two primary colors in a given color space. Additive secondaries Light (RGB) For the human eye, good primary colors of light are red, green, and blue. Combining lights of these colo ...

, color made from mixing primary colors * Secondary mirror, second mirror element/focusing surface in a reflecting telescope * Secondary craters, often called "secondaries" *

Secondary consumer A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

, in ecology * An obsolete name for the

Mesozoic The Mesozoic Era ( ), also called the Age of Reptiles, the Age of Conifers, and colloquially as the Age of the Dinosaurs is the second-to-last era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Creta ...

in geosciences *

Secondary feathers Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tai ...

, flight feathers attached to the ulna on the wings of birds

Science and nature

Society and culture