Etymology is the study of the history of words. It is also one of the most interesting and most enlightening aspects of linguistics. The basic question of etymology is
Where does [word X] come from?
The answer usually draws on a range of possible sources. But actually the mechanics of how words become part of a language are quite basic.
Either you steal a word from another language or you make a new word out of old ones. The first should with linguistical correctness be called borrowing and the second is an umbrella term for many different mechanics of word formation like compounding, derivation, clipping and the like.
The words of the language we speak at any given time do not usually tell us simply by looking at them where they come from. Therefore etymology has to go back in time.
In this week's example you have to go back to the middle ages. Old English (O.E.) was spoken from the 5th to the 12th century in what now is England. It was the language of Beowulf. In the Middle English (M.E.) period a bit later in the 14th century you find our word of the week in Sir Gawain and the Green Knight and in Geoffrey Chaucer's Canterbury Tales.
The O.E. (Old English) meaning of "enclosed land with buildings" is later split in two. The English keep the "land with buildings" and call it town. The Germans get the "enclosed" and call it Zaun. Say both out loud and you realise how obvious it really is.
