Longman Dictionary of Contemporary English - cloud

~1 n 1 a white or grey mass in the sky that consists of very small drops of water  (Dark clouds gathered overhead.) 2 a cloud of dust/smoke/gas etc a mass of dust etc in the air 3 something that makes you feel afraid or worried + of  (The clouds of war began to threaten our peaceful life.) a cloud on the horizon (=something that threatens to spoil a happy situation)  (The only cloud on the horizon was her mother's illness. | cast a cloud (=spoil a happy situation))  (The news that several competitors had been taking drugs cast a cloud over the event.) 4 on cloud nine informal very happy about something  (Adam was on cloud nine after the birth of his son.) 5 under a cloud informal if someone is under a cloud, people have a bad opinion of them because they have done something wrong  (He left the company under a cloud.) 6 be/live in cloud-cuckoo-land to think that a situation is much better than it actually is in a way that makes you seem stupid  (If Ben thinks he's getting a pay rise, he's living in cloud-cuckoo-land.) 7 every cloud has a silver lining used to say that there is something good even in a situation that seems very sad or difficult  (- see also have your head in the clouds head1 (11)) ~2 v 1 »GLASS« also cloud over/up if a transparent material such as glass clouds or something clouds it, you cannot see through it properly any more  (Steam had clouded the windows up.) 2 »LIQUID« also cloud up if a liquid clouds or if something clouds it, it becomes less clear  (Don't shake the barrel, you'll cloud the beer.) 3 »THOUGHTS/MEMORIES« to make someone less able to think clearly or remember things  (cloud sb's judgement/memory)  (Don't let your personal feelings towards this woman cloud your judgement.) 4 cloud the issue to make a subject or problem difficult to understand by introducing ideas or information that are not connected with it  (Bringing in unnecessary details at this stage will only cloud the issue.) 5 »FACE« also cloud over if someone's expression clouds or if something clouds it, they start to look angry or sad  (His face clouded when he saw her.) 6 »SPOIL STH« to make something less pleasant than it should have been  (Half a billion people vote in a general election clouded by violence and charges of poll-rigging.) 7 »COVER WITH CLOUD« to cover something with clouds  (Thick mist clouded the mountaintops.) cloud over phr v 1 if the sky clouds over, it becomes dark because it is full of black clouds  (The sky's really clouding over; I think we're in for a storm.) 2 if someone's expression clouds over, they start to look angry or sad  (Anne's face clouded over as she remembered.)