Alec Bamford uses this term in his comment on my last post. He first mentions it as a description of his own pronunciation of decade, by which I assumed he meant that his pronunciation one way or the other was randomly distributed, but he then goes on to use the term to describe contextually varying stress patterns in English. The example he gives is the California place name Del Mar: stress on ‘Mar’ in isolation, but on ‘Del’ when the name is followed by a stressed syllable (‘Del Mar residents’, for instance). There are many other cases: princess (in British English at least), as in ‘Princess Royal’, but ‘royal princess‘, or compact where second syllable stress as an adjective was normal until the phrase ‘compact disc’ came along, and the pattern ‘compact disc‘ established itself. In the 1980s, when this recording format became available, several Radio 3 announcers came to me at the BBC Pronunciation Unit and wanted me to recommend (which meant so far as staff announcers were concerned ‘dictate’) that the stress be maintained on the second syllable. I would not do this, on the grounds of normal English rhythmic patterns. I wonder whether my successors in the Unit have similar requests today.
It is contextual variation that has caused some bisyllabic words to change their pattern. Object seems always to have been stressed on the first syllable as a noun, and on the second as a verb, and by analogy with such words, new pairs, created when either a noun starts to be used as a verb, or vice versa, the same pattern has been imposed. Recent coinages often cause annoyance when the “wrong” stress pattern is used. In the 1970s and 1980s, there were many complaints to my office that dispute should always be stressed on the second syllable, whether as noun or verb, and Harriet Cass, then a young Radio 4 newsreader, commented to me that she was always horrified when she heard herself saying ‘dispute’ for the noun. (Harriet was once almost rendered incapable of reading the 1 o’clock news by being told by Professor Gimson at about 12.55 that he thought of her as the perfect example of an RP speaker of the younger generation. She ended her career as Chief Announcer at Radio 4.) ‘Dispute’ was then claimed by listeners to be the usage of trade union leaders (much heard on the airwaves in those days talking about industrial disputes), with the unspoken criticism that such people were uneducated and so unworthy of imitation. Again, I wonder if the Pronunciation Unit still gets such letters (or more likely email messages).
As an aside, I may be old-fashioned in my stressing of trajectory, but in the case of another word, trait, my pronunciation is the more modern one. My late brother, eight years my senior, but with identical upbringing to the age of 18 when we each went to university, pronounced this ‘tray’, as older dictionaries recommend. When I first heard him say this, I was puzzled as to what the word was he was using. I have always pronounced the final ‘t’. Why I continue to say ‘trajectory’, and where I got this from, I have no idea. Like most people, I suspect, I have an accent that contains a mixture of regional, social and period (older and newer) features.