I’m not speaking about the preliminary coat of paint but the word defined by Merriam-Webster as “a small book for teaching children to read; a small introductory book on a subject; a short informative piece of writing.” The dictionary gives the American pronunciation as rhyming with “dimmer,” and British as rhyming with “climber.” (Which is how both countries pronounce the paint thing.)
I have a strong and particular association with the word. The satiric magazine Mad, which was my bible as a kid, printed several dozen humorous “Primers” between 1956 and 1999. I distinctly recall my mother explaining to me how the word was pronounced–perhaps because, quite logically, I had said “pry-mer.”
As explained by Anne Curzan and Rebecca Kruth in their radio feature “That’s What They Say,”
The “primmer” pronunciation came into English from the Latin term “primarius” which meant “first.” This word can be traced back in written forms of English to the late 1300s. It originally referred to a Christian prayer book for laypeople (as opposed to clergy) that was often used to teach reading. By the 1500s, there are versions of these books that are only used to teach children to read.
In Britain, they go on, the “prye-mer” pronunciation emerged in the nineteenth century and became the dominant one in the twentieth, but “primmer” held on in the U.S.
Until recently, that is. On Facebook, I asked people how they pronounced the word and the results were illuminating. For the most part, it broke down by age: most of the people over 60 said “primmer,” and most under 60, “prye-mer.” The only non-American who responded was an English woman who has lived in the U.S. for some decades, and who said, “I don’t recall ever hearing ‘primmer.'” Of course, the word doesn’t come up that much.
The invaluable Youglish pronunciation website confirmed these impressions. It was hard to come up with a good sample size among U.K. speakers, because everybody seemed to be talking about paint or makeup, but 100 percent of the people referring “primer”-as-handbook said “prye-mer.” Among Americans, there was a perfect 8-8 split among the first sixteen examples, with a similar age breakdown as I saw on Facebook.
Notably, there were two videos featuring Bill Nye, the Science Guy (born 1955), and in both, so as to cover his bases, he said one pronunciation, then the other. In this clip, it comes it at the 1:52 mark.
notoneoffbritishisms.com 
I’m an American, though I lived overseas until I was 14, and my earliest memories are from when I was living in England. I’ve never in my life heard anyone use the “primmer” pronunciation.
But yeah, it’s not a word that comes up very often
Most words derived from primarius, such as prime, primacy, primarily are pronounced like primer (the first coat of paint). But then again, primitive and primrose are pronounced with a flat i, as in prim and proper. Since the first coat of paint and the first book have the same latin derivation, I’m not sure why Americans would pronounce them differently.
The words you mention are not derived from primarius ‘prayer book’ but from primus ‘first’; this is why they have different pronunciations. The ‘first coat of paint’ word is derived from the verb “to prime,” so obviously it has the same vowel as the verb.
Good afternoon, Ben!
I was taught to say “primmer.” I do remember some humorous piece about The Scarlet Letter, in which Hester Prynne[r] is referred to as “one of the New England Prynners.” I think it might have been by Art Buchwald.
Tim Orr
As a Brit who doesn’t really use the word in this context, it never occurred to me that it wasn’t pronounced ‘prymer’. I could understand it rhyming with ‘dreamer’, but ‘primmer’ just sounds odd to me.
My mother created and published what she always called a primer (though it was really a series of small school books) to teach people to read their own language. (My parents were the first to create an alphabet and a standard way to write that language.) And I cannot remember how she pronounced it. I think she said “pry-mer,” though I would say “primmer.” But then I grew up in a more correct linguistic and academic environment than she did, and I never saw her paint anything in her life. 🙂
I had assumed the word derived from the verb ‘to prime’:
prepare (someone) for a situation, typically by supplying them with relevant information.”the sentries had been primed to admit him without challenge.
Hence the pronunciation ‘prymer’
For what it’s worth, I am over 60 (70 in fact), from the UK, but have lived in the US for about 30 years – I think I have only ever heard “primmer” in the US, and “pry-mer” in UK, regardless of whether it is about paint or books!
British, but spent a couple of years in the States while children were in their early years of schooling. Never encountered the term “primer” for a handbook in the US nor in the UK, where children entered primary (pronounced “pry-muh-ree”) school.
As an English person I was only ever aware of the pronunciation rhyming with climber. I first encountered the “primmer” pronunciation in the film Contact (1997). The rich and reclusive character SR Hadden uses this pronunciation in an interview with Jody Foster’s Ellie Harroway, to add to my initial confusion Hadden was played by English actor John Hurt.
English East Midlands: I was not aware that ‘primer’ could be pronounced “primmer”. I think I saw Latin primers at school in the late 1960s, old books at the back of a cupboard. The textbook we used called itself something else.
I read Mad magazine when I visited the US; we didn’t have an equivalent in the UK. I brought copies back with me more than once. A few years ago I wrote a satire in the somewhat scattergun style of one of those issues of Mad, from the late 1970s or early 80s. Here it is:
https://www.quora.com/What-is-meant-by-being-British/answer/David-Griggs-7?__filter__=all&__nsrc__=notif_page&__sncid__=52663375868&__snid3__=70585978749
But different, in that Mad’s ridiculous stereotypes were of *other* nationalities – having their cake and eating it, mainstream America escaping pillory. Ultra-orthodox Jews copped it (I remember the caricature) and I suppose the few Irish or Italian Americans mad enough to believe they really were Irish or Italian would have been offended. I wonder if Italians have an equivalent of ‘Plastic Paddy’.