1cloud 
/ˈklaʊd/ noun
plural clouds /ˈklaʊd/ noun [count] 1 : a white or gray mass in the sky that is made of many very small drops of water
▪ The sun is shining and there's not a cloud in the sky. ▪ a rain cloud ▪ flying high above the clouds ▪ It stopped raining and the sun poked through the clouds. ▪ Thick cloud cover [=a large number of clouds in the sky] hid the moon. — see also mushroom cloud, storm cloud 2 a : a large amount of smoke, dust, etc., that hangs in the air
▪ a cloud of cigarette smoke ▪ clouds of steam/gas ▪ dust clouds
b : a large number of things (such as insects) that move together through the air in a group
▪ a cloud [=swarm] of bees 3 : a feeling or belief that a person or organization has done something wrong
▪ The company remains under a cloud of suspicion. [=people believe the company did something wrong] ▪ The team has been under a cloud since its members were caught cheating. ▪ There's a cloud of controversy/uncertainty/doubt hanging over the election.
▪ The sun is shining and there's not a cloud in the sky. ▪ a rain cloud ▪ flying high above the clouds ▪ It stopped raining and the sun poked through the clouds. ▪ Thick cloud cover [=a large number of clouds in the sky] hid the moon. — see also mushroom cloud, storm cloud
▪ a cloud of cigarette smoke ▪ clouds of steam/gas ▪ dust clouds
b : a large number of things (such as insects) that move together through the air in a group
▪ a cloud [=swarm] of bees
▪ The company remains under a cloud of suspicion. [=people believe the company did something wrong] ▪ The team has been under a cloud since its members were caught cheating. ▪ There's a cloud of controversy/uncertainty/doubt hanging over the election.
cast a (dark) cloud
: to cause people to stop trusting something
▪ The scandal cast a cloud over his presidency. [=people thought the President did something wrong] ▪ Several problems have cast a cloud on the program's future.
▪ The scandal cast a cloud over his presidency. [=people thought the President did something wrong] ▪ Several problems have cast a cloud on the program's future.
cloud on the horizon
: a problem that could appear in the future
▪ The only cloud on the horizon for the team is the age of its key players.
▪ The only cloud on the horizon for the team is the age of its key players.
every cloud has a silver lining — see silver lining
in the clouds
◊If you are in the clouds or you have your head in the clouds, you spend too much time thinking about love or about ideas that are not practical.
▪ Since he met Sara, he's been walking around with his head in the clouds.
▪ Since he met Sara, he's been walking around with his head in the clouds.
on cloud nine
informal : very happy
▪ He's been on cloud nine ever since she agreed to marry him.
▪ He's been on cloud nine ever since she agreed to marry him.
