Lit. 'plough-lands'. The long, narrow field of the long acre was necessitated by the plough-team of eight oxen. Such rigs were cumbersome and could not turn so neatly as the small team of two animals - or even people - pulling the light plough known as the aratra, a plough known to the Romans. The oxen needed more space to turn in, making the 'long acre' a practical solution. -
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.