Verb (5-dan, る, intransitive)
1. to groan; to moan
2. to roar; to howl; to growl
3. to hum (engine, wind, etc.); to buzz; to whiz; to sough; to make a low, dull sound
4. to ooh and aah (in admiration)
Verb (5-dan, る, transitive)
5. to sing in a strong, low voice (esp. traditional chant or recitation)
Verb (5-dan, る, intransitive)
6. to be about to burst; to overflow