ˈkran(ˌ)ru̇ḵ noun
( -s )
Etymology: alteration of earlier cranra, crainroch, probably modification of Scottish Gaelic crannreotha, crannreothadh, perhaps from crann to wither + reotha, reodhadh frost; perhaps akin to Old Irish crann tree and to Old English frēosan to freeze — more at hurst , freeze
Scotland : hoarfrost , rime