a. A visible body of very fine water droplets or ice particles suspended in the atmosphere at altitudes ranging up to several miles above sea level.
b. A mass of particles or droplets, as of dust, smoke, or steam, suspended in the atmosphere or existing in outer space.
a. A large moving body of things in the air or on the ground; a swarm: a cloud of locusts.
b. A collection of particles or other small entities: an electron cloud; a cloud of spores.
c. An opaque mass of particles suspended in water: a cloud of silt in the pond.
3. A dark region or blemish, as on a polished stone.
4. A state or cause of sadness, worry, or anger: At the bad news a cloud fell over the celebration.
5. A state or cause of confusion or misunderstanding: writing made difficult by a cloud of jargon.
6. A state or cause of suspicion or disgrace: A cloud of mistrust lingers among the signers of the treaty.
a. A large area of coordinated wireless internet service.
b. The collection of data and services available through the internet: stored company data in the cloud.
v. cloud·ed, cloud·ing, clouds
a. To cover or obscure with clouds: We could not see the moon because the sky was clouded over.
b. To make less clear or transparent: Smoke clouded the sky. Steam clouded the windows.
a. To make sorrowful, troubled, or angry: a bad memory that clouded his spirits.
b. To cause to appear sorrowful, troubled, or angry: Worry clouded her face.
a. To make difficult to know or understand; make obscure or uncertain: The economic downturn clouded the future of the project.
b. To confuse: Don't let your resentments cloud your judgment.
4. To cast aspersions on; sully: Scandal clouded the officer's reputation.
a. To become cloudy or overcast: The sky clouded over.
b. To become dark, obscure, or less transparent: The water in the tank clouded up.
2. To show sorrow, worry, or anger: His face clouded at the news.
in the clouds
under a cloud
Under suspicion or in a state of disgrace.
[Middle English, hill, cloud, from Old English clūd, rock, hill.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.