facula

UK: /ˈfækjʊlə/ US: (fak′yə lə)

WordReference Random House Unabridged Dictionary of American English © 2025

fac•u•la  (fak′yə lə), n., pl. -lae (-lē′). [Astron.]

1. an irregular, unusually bright patch on the sun's surface.

• Latin: little torch, equivalent. to fac- (stem of fax) torch + -ula -ule
• 1700–10

fac′u•lar, adj. 

Collins Concise English Dictionary © HarperCollins Publishers::

facula / ˈfækjʊlə/ noun ( -lae / -ˌliː/)

1. any of the bright areas on the sun's surface, usually appearing just before a sunspot and subject to the same 11-year cycle

Etymology: 18th Century: from Latin: little torch, from fax torch

ˈfacular adjective