The definition of muggy is hot, humid, sticky weather.(adjective)
A 90 degree day with 90 percent humidity is an example of a muggy day.
See muggy in Webster's New World College Dictionary
See muggy in American Heritage Dictionary 4
adjective mug·gi·er, mug·gi·est
Origin: Probably from Middle English mugen, to drizzle
Origin: ; akin to Old Norse mugga, a drizzle.
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