Secondary

Secondary may refer to:

Science and nature[edit]

Secondary emission, of particles
- Secondary electrons, electrons generated as ionization products
The secondary winding, or the electrical or electronic circuit connected to the secondary winding in a transformer
Secondary (chemistry), a term used in organic chemistry to classify various types of compounds
Secondary color, color made from mixing primary colors
Secondary mirror, second mirror element/focusing surface in a reflecting telescope
Secondary craters, often called "secondaries"
Secondary consumer, in ecology
An antiquated name for the Mesozoic in geosciences
Secondary feathers, flight feathers attached to the ulna on the wings of birds

Secondary (football), a position in American football and Canadian football
Secondary dominant in music
Secondary education, education which typically takes place after six years of primary education
- Secondary school, the type of school at the secondary level of education
Secondary market, an aftermarket where financial assets are traded