hoar

The word 'hoar' descends directly from the Old English 'hār', which meant "grey, venerable, old". This Old English term is cognate with Old High German 'hēr' ("distinguished, noble"), Old Norse 'hárr' ("grey-haired"), and further traces back to the Proto-Germanic 'hairaz'. The core semantic thread from its ancient roots to modern English is the concept of the pale, whitish-grey colour associated with age, frost, or antiquity. In contemporary use, it is largely restricted to poetic or descriptive literary contexts, most famously in the compound 'hoarfrost', where it perfectly captures the feathery, white ice crystals that give the appearance of an old, grey beard upon the landscape.

This is a simplex word of Old English origin. The entire word functions as a single, indivisible root meaning "grey, old, venerable".