The term 'THICK MIST' can be broken down into two words, 'THICK' and 'MIST'. The first word, 'THICK', is an adjective that means having a great physical depth or density. The second word, 'MIST', is a noun that refers to a cloud of tiny water droplets suspended in the air at or near the earth's surface. Together, these two words describe a type of fog, which is a collection of water droplets or ice crystals suspended in the air at or near the ground. FOGS, with four letters, is the crossword solution for this term.