A short written form of "Washington" — the American state in the north-west of the USA, near Canada. You see it in addresses, in lists of states, in old newspapers, and on forms where there is not much space. It is not spoken; if you are talking, you say the whole word "Washington". Note the full stop at the end: that dot is there because letters have been cut off the word, and leaving it out looks wrong in careful writing. These days the post office prefers the two-letter code WA, so "Wash." feels a little old-fashioned — you meet it more in books and older documents than on a modern envelope. One more thing worth knowing: it stands for the STATE, not for Washington, D.C., the capital city on the other side of the country. When people mean the capital, they write "Washington, D.C." or just "D.C.", never "Wash."