Remember the miniature cartoon character Inch High, Private Eye? Well, for those who have not been born yet in early 1970, this is “the world’s biggest little detective” who is literally one inch tall. So, how exactly much is that?
Inch is a unit of length. It is used mainly in the imperial and U.S. measurement systems, but it comes from the Ancient World. It derives from the Latin word uncia – the twelfth part of anything, a twelfth. Today inch designates 1/12 of a foot (≈30 cm) and equates to 2.5 cm. The word has been borrowed in a very early period, which explains why it does not exist in any other Germanic language, but in English.
Since inch represented such miniature dimensions, it soon started to denote small things – a trifle, a bit. That sense has been inherited from the Latin uncia, as such notion of the word can be traced as back as 3rd century BC - in the texts of the Roman playwright Plautus, for instance.
That use of inch as something small has given the expression “Give an inch!” It is a short form for “Give an inch and they will take an ell (mile)” and suggests that sometimes when you are generous to someone, the person will take advantage and will demand even more.
An ounce is another English word that derived from Latin uncia. It is a unit of weight equal to 1/12 of a pound, i.e. approximately 30g. The word came into English from the Old French "once"/"unce". A curious fact is that the word uncia itself has been adopted in Old English as "ynce" and eventually transformed in inch. The French borrowing "once"/"unce" gave the modern ounce.
Then why the abbreviation for that unit is oz and not oc for example? Although the word came from Old French, the abbreviation was borrowed from Italian. In Medieval Italian, the word was "onza", whereas the modern one is oncia.
What about the abbreviation of the pound – lb? What is the relation between these letters and the word? The pound is a unit of weight that equals to 455g. It comes from Latin "libra pondo" literally meaning "a pound by weight". The primary denotation of libra was scales, balance, but in combination with pondus (weight) was used as measurement in ancient Rome. The pound in English came from the Latin word for weight – "pondus", but the abbreviation (lb) derived from "libra".
The word pound could be recognized in the official currency of the United Kingdom - pound sterling, commonly known as the pound. Its abbreviation is another surprise – an L with a line across (£). As you probably guessed it right, the Latin, again, has to do with that issue. The Latin word "libra" stays for that symbol. Italians used the same one for their former currency – lira. The only difference was that there were two lines going through the Italian L.
The Latin libra gave the name of other world currencies. The name of the Turkish one is still lira. In Lebanon and Syria the local languages call their money the same way. It was ex-currency's name in Malta, San Marino, and the Vatican City too, before addopying the euro.