ADJ. dense, heavy, thick | freezing | patchy Drizzle and patchy fog are forecast. | swirling
QUANT. bank, blanket, patch The town was shrouded in a thick blanket of fog.
VERB + FOG be shrouded in
FOG + VERB cover sth, lie, shroud sth A freezing fog lay over the valley. | close in, come down, descend, roll in A dense fog came down in the afternoon. A heavy fog rolled in from the sea. | clear, disperse, lift The fog had lifted by late morning. | drift, swirl fog drifting over the water | obscure sth A bank of fog obscured the farmhouse.
FOG + NOUN patches
PREP. in/into (a/the) ~ We got lost in the fog. | through (a/the) ~ We drove slowly through the fog.