Phrase:
Pushing the envelope.
Meaning:
To attempt to extend the current limits of performance; to go beyond commonloy accepted boundaries.
Origin:
The envelope referred to is not the receptacle for sending letters but an area enclosed or enveloped.
In this way it has a lot in common with the phrase “beyond the pale”. This phrase refers not to a light colour, as in Procol Harum’s Whiter Shade of Pale, but to a stake or pointed piece of wood. It is virtually obsolete now except in the phrase “beyond the pale” and in the associated words paling (as in paling fence) and impale (as in Dracula movies). Pale came to mean an area enclosed by a paling fence, a safe area, so that “beyond the pale” came to mean leaving the safety of home. Inside the pale you were safe, outside the pale you were at risk, giving rise to the current meaning of unacceptable, outside agreed standards of decency.
