From dìcheall (“diligence”) + -ach.
dìcheallach
- diligent, industrious, hardworking
- Edward Dwelly (1911) “dìcheallach”, in Faclair Gàidhlig gu Beurla le Dealbhan [The Illustrated Gaelic–English Dictionary][1], 10th edition, Edinburgh: Birlinn Limited, →ISBN