A substance, such as mud or dust, that soils someone or something (OxfordDictionaries.com)
Metathesis of M.E. drit, drytt "mud, dirt, dung," from O.N. drit, cognate with O.E. dritan.
Cerk "dirt, filth."
Covered or marked with an unclean substance. → dirty ice, → dirty iceball model.
→ dirt + suffix -y.
Fr.: glace sale
Interstellar ice grains with graphite, silicates, or other chemical compounds adsorbed on their surfaces.
dirty iceball model
model-e golule-ye yax
Fr.: modèle de la boule de glace sale
A model for a → cometary nucleus proposed by Fred Whipple (1950-51), according to which the nucleus is a solid body (a few kilometers across) made up of various → ices (→ frozen water, → methane, → ammonia, → carbon dioxide, and → hydrogen cyanide) in which → dust is embedded. Dust particles are liberated when the ices vaporize as the → comet approaches the → Sun, and they get blown away by → solar radiation pressure, often forming impressive, gently curved → dust tails.