Essentially, to porkpie someone is to ignore them (if intentional) or to simply not notice them.
The etymology of "porkpie" is as follows: In a
weak attempt at improvised cockney rhyming slang, "porkpied" was used in place of "denied". That's it really. It sort of rhymes with denied.
Can be used as an interjection, a
noun, a
verb..
even a way of life, if you're so inclined - making porkpie a valuable addition to anyone's vocabulary.
Can be abbreviated to 'pied.
More experienced users of the word have been known to say it with an accompanying gesture - any formation of the hands, which alludes to the view through a cross-section of a porkpie, will do. A plan view of such a porkpie is generally unacceptable, however, and can
even be interpreted as an
insult in some circles.