- Noun. An elementary textbook introducing a topic, or teaching basic concepts.
- Noun. An elementary book for teaching children to learn the alphabet and to read, write and spell.
- Noun. (biology) A single-stranded nucleic acid molecule required for the initiation of replication of a DNA molecule.
- Noun. Any substance used to start a fire.
- Noun. A small charge that burns furiously when given sufficient electrical current (Explosive primer) or when struck with force (percussion caps) that ignites the main combustable substances in explosives or ammunition.
- Noun. A layer of paint designed to underlay a topcoat, used to enhance the adhesion and durability of the topcoat and help in protection of the surface.
- Noun. A device used to circulate gasoline into the ignition chamber of an engine.