Aitken nucleus

noun

Ait·​ken nucleus ˈāt-kən- 

meteorology

: a microscopic aerosol particle in the atmosphere that encourages condensation to gather into a droplet

Using air samples collected from a 65-foot tower in a eucalyptus forest in Portugal, the researchers found an abundance of tiny aerosols, known as Aitken nuclei, that could only have been produced locally.

—Henry Fountain, New York Times, 3 Nov. 1998

Word History

Etymology

after John Aitken †1919 Scottish meteorologist and engineer

First Known Use

1906, in the meaning defined above

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!