It won’t have escaped your notice that we are in the midst of celebrating the Queen’s Diamond Jubilee.
I am struck by the number of commentators on British television whom I’ve noticed pronouncing diamond as ˈdaɪmənd rather than ˈdaɪəmənd (or the smoothed variants of the latter ˈdaəmənd, ˈdaːmənd).
In LPD I mark ˈdaɪmənd with the sign §, indicating that as far as BrE is concerned I consider this ‘non-RP’. (In current terminology, you could say that it is ‘deprecated’.) For AmE, on the other hand, I perhaps go too far in giving only this possibility.
I was wondering, has ˈdaɪmənd always been around, though presumably always considered incorrect? Or is it a recent import from AmE? Anyhow, why do Americans tend to use this pronunciation, given that it does not accord with the spelling?
On consulting the OED, I find that ˈdaɪmənd, contrary to my expectation, has a considerable history in BrE. The word diamond appears to be etymologically cognate with adamant, via late Latin diamas, diamant- from the Greek ἀδάμας, ἀδάμαντ- adámas, adámant- ‘untamed, unalterable, unbreakable’.
The a of the middle syllable has tended to disappear since the 16th cent., as shown by the spelling di'mond, dimond. Sheridan and other early orthoepists recognize the dissyllabic pronunciation, but most recent authorities reckon three syllables. In Shakespeare the word is more frequently a trisyllable; but it is very generally dissyllabic in Pope, Thomson, Young, Cowper, Keats, and Tennyson.
So perhaps I’d better remove the § mark. And this word will be a good candidate for inclusion in the next pronunciation preference poll I conduct.
The only other dia- word I can find with a similar pronunciation is diaper. In AmE it seems usually to be ˈdaɪpɚ, to rhyme with wiper, though Webster’s Collegiate adds ˈdaɪəpɚ as an ‘also’ pronunciation. Since this word is not used in modern BrE (though it is found in Shakespeare), it is difficult to say whether there is any established BrE pronunciation of it.
Other candidates? As far as I know, no one says *ˈdaɪdem for diadem or *ˈdaɪgræm for diagram. Does anyone say ˈdaɪlekt for dialect? I wonder.