What does muggy mean?
Muggy is an adjective describing air, weather, or enclosed spaces that are unpleasantly damp and humid, often with an additional feeling of closeness or stuffiness. It is especially common in descriptions of hot summer days, crowded rooms, and weather that makes people feel uncomfortable. The word is neutral rather than highly formal, and its negative impression usually comes from the physical discomfort it conveys rather than from any moral judgment. Muggy can describe a place, a period of time, or an atmosphere: a muggy afternoon, a muggy train carriage, or the muggy atmosphere before a storm. Although damp and humid are close synonyms, muggy often suggests oppressive humidity and air that does not circulate freely. In contrast, muddy refers to mud rather than moisture in the air.
adjectiveUnpleasantly damp, humid, and often close or stuffy, especially when describing the weather or the air in an enclosed space.
- Unpleasantly damp, humid, and often close or stuffy, especially in weather or in an enclosed space.
"The afternoon was muggy, with heavy clouds trapping the heat and humidity."
"It was a muggy morning, and the windows had fogged over by noon."
"The crowded train car was hot and muggy, with the smell of wet coats hanging in the air."
If the air feels damp and airless enough to make a room feel oppressive, it is probably muggy.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does muggy come from?
Muggy is an English word formed in the early 18th century from the base mug and the adjectival suffix -y. The base has several older senses, and the precise semantic development leading to the modern weather sense is not entirely straightforward. Modern forms such as mugshot and mugger are likewise formed from mug, though their meanings developed along separate lines.
Related word forms
How muggy is actually used
Muggy is a common descriptive word with a slightly negative or uncomfortable connotation. It suggests not only moisture but also a sense of stuffiness, oppressive heat, or air that feels difficult to breathe.
Easily confused with muggy
Muggy describes damp, humid, and often airless conditions, whereas muddy describes something covered in or contaminated with mud.