A sizing that is applied to a wall to prepare the surface for paint is an example of a primer.
A book that has very simple and easy words and sentences (like "See Jane run.") designed to help a child learn to read is an example of a primer.
- A small cap, tube, etc. containing an explosive, used to set off a main charge.
- Paint, sizing, etc. used as a preparatory coating on a raw surface.
Kennedy's New Latin Primer (an introductory grammar, published 2008)
Origin of primer
- Middle English devotional manual from Norman French from Medieval Latin prīmārium from neuter of prīmārius first from Latin from prīmus prime
From American Heritage Dictionary of the English Language, 5th Edition