from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Chiefly Northeastern U.S. A sky covered with many small cirrocumulus or altocumulus clouds, resembling the markings found on a mackerel. Also called regionally buttermilk sky.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. a sky filled with a regular pattern of altocumulus clouds somewhat resembling the skin of a mackerel.
from the GNU version of the Collaborative International Dictionary of English
- n. a sky flecked with small white clouds; a cirro-cumulus. See Cloud.
- n. A sky filled with rows of cirrocumulus or small altocumulus clouds.
from The Century Dictionary and Cyclopedia
- n. A sky in which the clouds have the form called cirro-cumulus—that is, are broken into fleecy masses three, four, or more times as long as they are wide, and arranged in parallel groups. Also called mackerel-back sky.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a sky filled with rows of cirrocumulus or small altocumulus clouds
Sorry, no etymologies found.