郁郁 (yù yù) is a literary reduplicated adjective (AA pattern) with several distinct senses: it can describe lush vegetation (often in the chengyu 郁郁葱葱), a melancholy mood (seen in 郁郁寡欢), or a rich, pleasant fragrance. Which sense is active depends entirely on context; the word itself carries no inherent connection between vegetation, mood, and smell in English, so learners must rely on surrounding words to disambiguate.