coma - (astronomy) the luminous cloud of particles surrounding the frozen nucleus of a comet; forms as the comet approaches the sun and is warmed

nebula - an immense cloud of gas (mainly hydrogen) and dust in interstellar space

physical phenomenon - a natural phenomenon involving the physics of matter and energy

aerosol - a cloud of solid or liquid particles in a gas

cosmic dust - clouds of particles or gases occurring throughout interstellar space

dust cloud - a cloud of dust suspended in the air

mushroom cloud, mushroom-shaped cloud, mushroom - a large cloud of rubble and dust shaped like a mushroom and rising into the sky after an explosion (especially of a nuclear bomb)

cirrocumulus, cirrocumulus cloud - a cloud at a high altitude consisting of a series of regularly arranged small clouds resembling ripples

cirrostratus, cirrostratus cloud - a thin uniform layer of hazy cloud at high altitude

cirrus cloud, cirrus - a wispy white cloud (usually of fine ice crystals) at a high altitude (4 to 8 miles)

cloud bank - a layer of clouds seen from a distance

condensation trail, contrail - an artificial cloud created by an aircraft; caused either by condensation due to the reduction in air pressure above the wing surface or by water vapor in the engine exhaust

cumulonimbus, cumulonimbus cloud, thundercloud - a dark cloud of great vertical extent charged with electricity; associated with thunderstorms

cumulus, cumulus cloud - a globular cloud

mother-of-pearl cloud, nacreous cloud - a luminous iridescent cloud at a high altitude that may be seen when the sun is a few degrees below the horizon

nimbus, nimbus cloud, rain cloud - a dark gray cloud bearing rain

sky - the atmosphere and outer space as viewed from the earth

storm cloud - a heavy dark cloud presaging rain or a storm

stratus, stratus cloud - a large dark low cloud

atmospheric phenomenon - a physical phenomenon associated with the atmosphere

water vapor, water vapour - water in a vaporous form diffused in the atmosphere but below boiling temperature

irreality, unreality - the state of being insubstantial or imaginary; not existing objectively or in fact

gloominess, glumness, gloom - an atmosphere of depression and melancholy; "gloom pervaded the office"

suspicion - the state of being suspected; "he tried to shield me from suspicion"

insect - small air-breathing arthropod

animal group - a group of animals

infestation, plague - a swarm of insects that attack plants; "a plague of grasshoppers"

darken - make dark or darker; "darken a room"

fog up - get foggy; "The windshield fogged up"

haze - become hazy, dull, or cloudy

cloud over, cloud up, overcloud - become covered with clouds; "The sky clouded over"

cloud over, cloud up, overcloud - become covered with clouds; "The sky clouded over"

conceal, hide - prevent from being seen or discovered; "Muslim women hide their faces"; "hide the money"

overshadow - cast a shadow upon; "The tall tree overshadowed the house"; "The tragedy overshadowed the couple's happiness"

billow, wallow - rise up as if in waves; "smoke billowed up nto the sky"

impress, strike, affect, move - have an emotional or cognitive impact upon; "This child impressed me as unusually mature"; "This behavior struck me as odd"

mar, deflower, impair, vitiate, spoil - make imperfect; "nothing marred her beauty"

spot - mark with a spot or spots so as to allow easy recognition; "spot the areas that one should clearly identify"

harlequin - variegate with spots or marks; "His face was harlequined with patches"

speckle, stipple - produce a mottled effect; "The sunlight stippled the trees"

dull - make less lively or vigorous; "Middle age dulled her appetite for travel"