Dense fog definitions

Dense fog

1) Navigation hazard 2) Pea soup
Found on https://www.crosswordclues.com/clue/dense-fog

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Dense Fog

a fog in which the visibility is less than one-quarter mile.
Found on http://www.encyclo.co.uk/local/22268

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Dense fog

A fog in which the visibility is less than one-quarter mile.
Found on http://www.timeanddate.com/weather/glossary.html

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