a substance used as a preparatory coat on wood, metal, or canvas, especially to prevent the absorption of subsequent layers of paint or the development of rust

apply three coats of primer

new plaster should be treated with a primer

a cap or cylinder containing a compound which responds to friction or an electrical impulse and ignites the charge in a cartridge or explosive

the nitro-cellulose is ignited by the spark that comes from the primer

a small pump for pumping fuel to prime an internal combustion engine, especially in an aircraft

no more than four pumps of the primer usually suffice

a molecule that serves as a starting material for a polymerization process

the duplex RNA primer cannot initiate DNA replication

an elementary textbook that serves as an introduction to a subject of study or is used for teaching children to read

a first-year philosophy primer