UT, written in two capital letters, is the official short form of the American state Utah. It is not a word you say out loud — nobody reads 'UT' aloud as anything but 'Utah'. It belongs to writing, and to one kind of writing in particular: addresses. Every US state has a two-letter code of this kind, set by the postal service, and it sits between the city and the ZIP code: 'Salt Lake City, UT 84101'. You will also see it in tables, on forms, on weather maps, in sports results, and anywhere a page is too narrow to spell out fifty state names.

A small point of style: these postal codes take no full stops. Write 'UT', not 'U.T.'. And they are used in addresses and lists, not in ordinary sentences — you would not write 'I have never been to UT'; you write 'I have never been to Utah'.

Though actually, two capital letters can stand for many different things, and this is worth knowing so you are not tripped up. In American conversation, 'UT' often means the University of Texas, or the University of Tennessee, or the University of Utah, depending on which part of the country you are in — and there people do say the letters aloud, 'you-tee'. In science writing, UT can mean Universal Time. Context tells you which. Here, though, the entry is the state.