mist noun definition in Sky topic from the Oxford Advanced Learner's Dictionary

mist

 noun: Sky topic
[uncountable, countable] a cloud of very small drops of water in the air just above the ground, that make it difficult to see The hills were shrouded in mist. Early morning mist patches will soon clear. The origins of the story are lost in the mists of time (= forgotten because it happened such a long time ago). (figurative) She gazed at the scene through a mist of tears.