Verb (5-dan, る, intransitive)
1. to become muddy; to become cloudy; to get impure (of a liquid, gas, etc.)
2. to become dull (of a sound, color, etc.); to become hoarse
3. to become impure (of a heart, society, etc.); to be corrupted; to be polluted
4. to become voiced; to add voiced consonant marks