1) Dense fog 2) Dense fog metaphor 3) Dense fog, metaphorically 4) Describing fog 5) Epitome of thickness 6) Exemplar of thickness 7) Fog metaphor 8) Fog, slang 9) Foggy-day fare 10) Green appetizer 11) Green bowlful 12) Green metaphor for fog 13) London fog 14) Metaphor for dense fog 15) Meteorological metaphor 
Peasoup is slang for a dense fog.