A parchment; specifically either of two rolls of parchment for recording receipts (called in Latin the pellis receptorum) and issues (called in Latin the pellis exituum), formerly kept at the Exchequer.

With the and capital initial. The Office of the Exchequer in which these rolls were kept.

A stake or post at which to practise sword-strokes.

In full "Pell equation", "Pell's equation". A Diophantine equation of the form y 2 − ax 2 = 1, where x and y are integer variables, and a is an integer constant.