Muggy means warm, damp and uncomfortable. A muggy afternoon, muggy and still, muggy weather.
It is the word for heat that sweat cannot fix, since the air is already too wet to take any more. Britain uses it constantly for the few weeks a year it applies, and close is the other word for the same thing.
1adjectivemuggyWarm, damp and uncomfortable.
“It's so muggy today that my shirt is sticking to my back.”
muggy is a quality.
From a dialect word mug meaning mist or drizzle, from Old Norse mugga.
Old Norse
mugga — drizzle, mist
English, today
muggy
Built from
From dialectal English mug (“fog, mist; Scotch mist”) y, ultimately from Old Norse mugga (“drizzle, mist”); borrowed some time before 1390, when a derived verb, mugen (“of a fog: to drizzle”), is attested.
Etymology from Wiktionary, CC BY-SA