mugginess Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. a condition of warm and humid weather. Example Sentence The mugginess made it hard to breathe. More Example Sentences Mugginess often comes before a rainstorm. Synonyms humidity; dampness; stickiness Antonyms dryness; aridity; coolness Hear It! Say It! Write It! mugginess Switch to cursive Start Share with your friends: