Usage: often attributive
Etymology: Middle English, rock, cloud, from Old English clūd; perhaps akin to Greek gloutos buttock
Date: 14th century
1. a visible mass of particles of condensed vapor (as water or ice) suspended in the atmosphere of a planet (as the earth) or moon
2. something resembling or suggesting a cloud: as
a. a light filmy, puffy, or billowy mass seeming to float in the air <a cloud of blond hair> <a ship under a cloud of sail> b. (1) a usually visible mass of minute particles suspended in the air or a gas (2) an aggregation of usually obscuring matter especially in interstellar space (3) an aggregate of charged particles (as electrons) c. a great crowd or multitude ; swarm <clouds of mosquitoes> 3. something that has a dark, lowering, or threatening aspect <clouds of war> <a cloud of suspicion> 4. something that obscures or blemishes <a cloud of ambiguity> 5. a dark or opaque vein or spot (as in marble or a precious stone) II. verb Date: 1562 intransitive verb 1. to grow cloudy — usually used with over or up <clouded over before the storm> 2. a. of facial features to become troubled, apprehensive, or distressed in appearance <her face clouded with worry> b. to become blurry, dubious, or ominous — often used with over <the outlook is clouding over> 3. to billow up in the form of a cloud transitive verb 1. a. to envelop or hide with or as if with a cloud <smog clouded our view> b. to make opaque especially by condensation of moisture <steam clouded the windows> c. to make murky especially with smoke or mist <smoke clouded the sky> 2. to make unclear or confused <cloud the issue> 3. taint, sully <a clouded reputation> 4. to cast gloom over <cloud prospects for success>
New Collegiate Dictionary. 2001.