From Wiktionary, the free dictionary
From Middle Irish dúr, from Latin dūrus (“hard”).
dùr
- obstinate, stubborn
- sullen, sour, dour, stolid
- stiff, rigid
- Edward Dwelly (1911) “dùr”, in Faclair Gàidhlig gu Beurla le Dealbhan [The Illustrated Gaelic–English Dictionary][1], 10th edition, Edinburgh: Birlinn Limited, →ISBN