- a dense fall of fine powdery snow liable to pile up into drifts. This is a word from Orkney and Shetland. A moor had fa’n a’ the heel [whole] day (Walter Dennison The Orcadian Sketch-Book 1880).
The choking sense associated with powdery snow can also be used to describe nasal tubes choked with phlegm, so mooran wi the cauld in Orkney means that your nose is all blocked up with a cold.