From Wiktionary, the free dictionary
aon- + margadh (“market”)
aon-mhargadh m
- monopoly
- Edward Dwelly (1911) “aon-mhargadh”, in Faclair Gàidhlig gu Beurla le Dealbhan [The Illustrated Gaelic–English Dictionary][1], 10th edition, Edinburgh: Birlinn Limited, →ISBN