hrīm

Rime comes from Old English hrīm, from Proto-Germanic *hrīmaz (frost, hoarfrost). The word has been in English for over twelve hundred years. It originally referred to any frost, but in modern usage it has narrowed to a specific type: ice that forms when supercooled water droplets in fog freeze on contact with surfaces. Rime frost creates feathery, white, opaque crystals that grow into the wind, building up on the windward side of objects.

Rime is distinct from hoarfrost, though the two are often confused. Hoarfrost forms from water vapor (gas to solid, like dew but frozen). Rime forms from liquid water (liquid to solid, fog droplets freezing on impact). The visual difference: hoarfrost is delicate and crystalline. Rime is chunky and opaque. Both are beautiful. The physics are different.

Samuel Taylor Coleridge published The Rime of the Ancient Mariner in 1798, using the archaic spelling 'rime' to give the poem a medieval atmosphere. The poem is about an old sailor who shoots an albatross and suffers supernatural punishment. The title uses 'rime' to mean 'poem' or 'tale' (from Old French rime, ultimately from Old High German rīm, 'number, series') — not the frost. But the ambiguity is productive: the mariner's ship sails through ice. Both meanings haunt the poem.

The spelling 'rime' for a poem and 'rime' for frost are homographs from different etymological sources. Old English hrīm (frost) and Old French rime (verse, rhyme) converged in the same spelling by coincidence. Coleridge exploited the collision. Most readers assume 'rime' means 'rhyme.' It does. It also means ice. The poem lives in both meanings.