Etymology
Advertisement
primer (n.1)

late 14c., "prayer-book, layperson's devotional manual," also "school book" (senses not distinguished in Middle English, as reading was taught from prayer books), from Medieval Latin primarium, from Latin primus "first" (see prime (adj.)), on the notion of "a first book." The word also might be all or in part from prime (n.) in the time sense on the same notion as a book of hours. Meaning "small introductory book on any topic" is from 1807.

Related entries & more 
Advertisement
primer (n.2)
"explosive cap," 1819, agent noun from prime (v.).
Related entries & more 
primer (n.3)

"first layer of dye or paint," 1680s, agent noun from prime (v.).

Related entries & more 
abecedary (n.)
"primer, alphabet table," mid-15c., from Medieval Latin abecedarium "an ABC book," neuter of adjective abecedarius, used as a noun, from the first four letters of the Latin alphabet. Abecedarian (adj.) is attested from 1660s.
Related entries & more