1. n. (historical, Catholic ecclesiastical) A prayer or devotional book intended for laity, initially an abridgment of the breviary and manual including the hours of the Virgin Mary, 15 gradual and 7 penite
2. n. (historical, Protestant ecclesiastical) Similar works issued in England for private prayer in accordance with the Book of Common Prayer.
3. n. A children's book intended to teach literacy: how to read, write, and spell.
1545, The A.B.C. Primers
4. n. An introductory text on any subject, particularly basic concepts.
5. n. (New Zealand) An elementary school class; an elementary school student.
6. n. Any substance or device, such as priming wire or blasting cap, used to ignite gunpowder or other explosive.
7. n. (obsolete, rare) A person who primes explosives.
8. n. A substance used to prime wood, metal, etc. in preparation for painting.
9. n. A layer of such a substance.
10. n. A layer of makeup that goes beneath the foundation; undermakeup.
11. n. (obsolete, rare) A person who primes wood, metal, etc.
12. n. (biochemistry) A molecule which initiates the synthesis of an enzyme, (especially) a single-stranded nucleic acid molecule which initiates DNA replication.
13. n. (medicine, zoology) A pheromone which interacts first with the endocrine system.
14. n. A device used to prime an internal combustion engine with gasoline, (especially) in airplanes.
15. n. A person who prunes trees.
16. adj. (obsolete) First in time, initial, early.
17. adj. (obsolete) First in importance, premier.
18. adj. (obsolete, rare) First in position, foremost.