A Little Too Mainstreamish

I've been collecting noun-adjectives for a long time:  nouns like 'key' or 'mammoth' or 'routine' that are popularly used as adjectives. A key decision,  a mammoth jumble sale, a routine inspection.  The problem (or the joke) occurs when the noun-adjectives are then qualified with adverbs; 'very key' or 'overly mammoth'; or, as heard on TV not long ago, "bad weather seems to be becoming more routine". So I was surprised and delighted to find in the Radio Times recently a brief article that described camel-racing with robot jockeys (yes, that's right) in Arabia as "actually a very mainstream sport".

What surprises me even more is that the two-volume Shorter Oxford Dictionary (2007 edition) does not include the term 'mainstream' at all - not even as a noun.  Nor do various other dictionaries I have looked into: with the exception of the BBC  English Dictionary of 1993.  It gives as one example the noun phrase 'mainstream education'.  That doesn't imply that the word mainstream is here intended as an adjective:  it is a quite respectable 'noun in apposition' (compare 'football stadium'; 'book cover'; 'carriage way';  'twentieth century prime minister'; 'tooth decay'; 'garden gnome').  It is only when we find a writer adding a qualifying adverb like 'particularly' or 'genuinely' or 'utterly' or 'very' or 'more' to one of these 'nouns in apposition' that he or she reveals a lack of feeling for the functions of words.  Or 'word insensitivity' if we want to be appositional.

A Little Too Mainstreamish