envelope

A calculation or mathematical formulation that is approximated in a quick, informal, and rough manner, as might be sketched out on a scrap of paper (such as the back of an envelope). When it came time to pay the bill, we had to do some back-of-the-envelope calculations to figure out who owed how much.

Any event, celebration, or ceremony, no matter how trivial or unremarkable, that one attends purely for the sake of visibility. Often said in relation to celebrities or media personalities who make a point of attending anything that will give them more public exposure. In a bid to cultivate a media buzz around herself, the Internet sensation has been to the openings of films, book launches, and celebrity galas. With the way she carries on, she'd even go to the opening of an envelope!

Fig. to expand the definition, categorization, dimensions, or perimeters of something. The engineers wanted to completely redesign the product, but couldn't push the envelope because of a very restricted budget.

to move beyond the limit of what has usually been done or was the accepted standard TV shows are really pushing the envelope by showing so much sex and violence.

Exceed the limits of what is normally done, be innovative, as in They are pushing the envelope in using only new fabrics for winter clothing. This idiom comes from aviation, the envelope alluding to the technical limits of a plane's performance, which, on a graph, appear as a rising slope as limits of speed and stress are approached and falls off when the capacity is exceeded and the pilot loses control; safety lies within these limits, or envelope, and exceeding them exposes pilot and plane to risk. [Slang; late 1960s]

To exceed or try to exceed the existing limits of a discipline or activity.