Skip to main content
Dictionary
Store
Blog
World
Help
Advertise
Chat
System Status
Information Collection Notice
Trademark Concerns
reCAPTCHA Privacy
Terms of Service
reCAPTCHA Terms
Privacy Policy
Accessibility
Report a Bug
Data Request
Contact Us
Security
DMCA
© 1999–2026 Urban Dictionary ®
Mugs
Tees
Hoodies
Pro Customization
Create unique products with your own words and definitions
Preview
Personalize Your Design
Your Word
Your Definition
Part of Speech: Noun Definition: A rare and powerful type of thundercloud characterized by its immense size, towering vertical development, and potential to produce intense rainfall, lightning, and strong winds. Aquilonimbus clouds often form in regions where cold polar air collides with warmer air masses. Etymology: "Aquilonimbus" is a portmanteau word formed by combining "aqui-" from "aqua" (Latin for water) and "nimbus" (a type of cloud). "Aquilo" is a Latin term for the north wind, often associated with cold and polar air. "Nimbus" refers to a type of cloud that brings precipitation. The term is constructed to reflect the cold and stormy nature of these clouds, which result from the clash between cold and warm air masses. Term coined by Professor Justin Ho Guo Shun
Text fits
Save
Cancel