This is a Polish-Slav surname of uncertain origins. It is probably a 'short form' of a patronymic nickname surname such as 'Tschorn', and in that respect would be a form of the English surname 'Black', originally a literal description for a dark or swarthy person, or more logically a description of national origins such as Celt, Gael, Slav or Mongol, all of whom were black haired. 'Tchir', also recorded as 'Tchor' and 'Tchin', would seem to be cognate with the Slav 'Tschorn', the Polish 'Czarny', the Czech 'Cerny', the German 'Schorn' and the Russian 'Cherny', all of whom mean 'dark skinned', and all of whom are subject to local dialectal and spellings changes. Polish descriptive surnames usually have the endings of 'ak' or 'ik', depending on whether the holder is male of female, and in this case there are recordings as 'Tschornik' which is not dissimilar. Polish and Eastern European registers generally are both sparse and of poor quality, reflecting the centuries of upheaval which have benighted these countries. In the case of 'Tchir' we have a particular curiosity in that the registers clearly show a an unexplained spelling change from 'Tchin' to 'Tchir'. On December 18th 1846 Daniel Tchin and his wife Rosalia, nee Warcholik, were witnesses at the christening of their daughter Justina at Mecina, Rzeszowskiego. However on July 6th 1849, at the christening of their son Johannes at the same place, the family are recorded as Daniel and Rosalia Tchir. Unfortunately our records are unable to show whether this is a misspelling, or the creation of the new surname. The first recorded spelling of the family name is shown to be that of Adamus Tchor, which was dated September 20th 1805, who was christened at Lug, Rzeszowskiego, Poland, during the reign of Czar Alexander 1st of Russia, 1801 - 1825. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.