an 18-point type of a size larger than Columbian, formerly used for Bibles.
Origin of great primer
First recorded in 1675–85
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for great primer
It was not until 1757 that he published his first work, a Virgil in royal quarto, with great-primer letters.This Simian World|Clarence Day
I saw all this as plainly as if it had all been printed in great-primer type, instead of working itself out in her features.The Poet at the Breakfast Table|Oliver Wendell Holmes, Sr.
British Dictionary definitions for great primer
(formerly) a size of printer's type approximately equal to 18 point
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012