Secondary

Secondary is an adjective meaning "second" or "second hand". It may refer to:

• The group of (usually at least four) defensive backs in American football and Canadian football
• An obsolete name for the Mesozoic in geosciences
• The secondary winding, or the electrical or electronic circuit connected to the secondary winding in a transformer
• Secondary color
• Secondary consumers in ecology Trophic dynamics
• Secondary dominant in music
• Secondary education
  • Secondary school - The type of school at the secondary level of education
• Secondary market, an aftermarket where financial assets are traded
• Secondary market offering
• Secondary mirror, second mirror element/focusing surface in a reflecting telescope
• Secondary neoplasm
• Secondaries, the second-largest group of remiges (wing feathers), which attach to the inner lower arm
• Private equity secondary, investment in an existing private equity fund or other alternative asset