Adam Jack Aitken (19 June 1921 – 11 February 1998) was a Scottish lexicographer and leading scholar of the Scots language.
Aitken was born on 19 June 1921 in Edinburgh, grew up in Bonnyrigg, Midlothian, and was educated at Lasswade High School. He was the only son and eldest of the three children of Adam Aitken, a miner, and his first wife Alexandrina Sutherland, who died when Jack was about nine. He suffered neglect as a step-child, but his minister, Rev. Oliver Dryer, helped him to leave home at the age of sixteen. He was able to continue his education thanks to a school bursary. As the son of a miner, he received further bursaries that allowed him to enter the University of Edinburgh in 1939. He served as a lance bombardier in the Royal Artillery during World War II in North Africa and Sicily. He took part in the Normandy landings landing at Port en Bessin D Day + 2, he drove to join 151 Brigade of the 50th Division beyond Bayeuk. He fought at Tilly sur Seulles and Villers Bocage. He was commended for bravery by Field Marshal Montgomery in 1944 during the campaign in France. He rose to the rank of Sergeant Major.
He graduated MA with First Class Honours in English Language and Literature in 1947. In 1948 he was appointed Assistant to Sir William Craigie, the Editor of A Dictionary of the Older Scottish Tongue (DOST) and became Editor of DOST on Craigie’s retirement in 1956. When he took over editorial responsibility for DOST, Aitken instituted a new reading programme that approximately doubled the list of works excerpted for the dictionary, correcting the bias towards verse and literary prose. Aitken's editorship began with the letter J, and the impact of the new reading programme is seen from the third volume onwards.
Aitken was one of the first to appreciate the potential of the computer for research in the Arts. Although computer methods arrived too late to be of central importance in the collection process for DOST, he set up, with Paul Bratley and Neil Hamilton-Smith, the Older Scots Textual Archive, a computer-readable archive of over one million words of Older Scots literature.