下沉，沉没，淹没

1. to sink, to go under, to submerge

Godan verb with 'mu' ending intransitive verb

2. to go down (e.g. sun), to set, to descend

intransitive verb Godan verb with 'mu' ending

感到沮丧，变得低落，变得阴郁

3. to feel depressed, to become subdued, to become somber

intransitive verb Godan verb with 'mu' ending