Pat Durkin in <mOtoh.30129$hI.27721@newssvr11.news.prodigy.net>:
> > Gamma in <121220060555419694%gamma@coldmail.com>:
> >
[quoted text clipped - 6 lines]
> >
> > Precocious.
It's difficult to come up with a single word or phrase which covers
all three of the OP's examples, in the more formal manner requested,
since they're merely dismissive insults. Is it possible to insult
someone formally? I have my doubts. Still, I would say precocious
covers the first two (if not quite the third, which is of a slightly
different order).
> Well, I would say "impertinent", or perhaps "saucy", although the latter
> is often used in another context that indicates high-spirited or perky.
I'm not sure about 'saucy' - it has a distinctly archaic feel to it.
One imagines women of easy virtue being saucy; or one thinks of its
naval connotations, such as:
"We sail the ocean blue,
And our saucy ship's a beauty..."
> To me, while "precocious" is formal, it connotes a knowledge in advance
> of what one expects of a child.
Not wishing to be dictionary-bound, but my Pocket Oxford has it that
precocious is 'often derogative'. I would qualify that by saying that
as is often the case, the meaning of a word may be altered by its
context. So we might have 'a precocious talent', which is almost
complimentary; or we might have 'precocious little git' which
decidedly is not.
Perhaps the latter phrase would serve well in this case, since the
adolescent in question may not understand the insult, and so lose face
by not appearing to 'know it all' after all.

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Col Morrison