Definitions by R. Pompeo

mossback 

A slang term used to refer to those, often from the Pacific Northwest, who prefer drizzly, overcast weather to sunshine. The term alludes to these people preferring to spend so much time out of the sun that moss grows on their backs.

"What do you mean you don't want to hang at the beach?! It's gloriously sunny in Seattle!"
"I don't know, man. I'm kind of a mossback. I miss the rain. I can just hang inside with a sweater and a good book."

mossback by R. Pompeo March 17, 2016