-ru Godan/u-verb

1. to become muddy; to become cloudy; to become turbid; to become impure (of a liquid or gas)
2. to become dull (of a sound, color, etc.); to become indistinct; to become fuzzy; to become hoarse
3. to become impure (of one's heart, a society, etc.); to be corrupted; to be polluted
4. to become voiced (of a consonant); to be pronounced as a voiced sound