唸る, 呻る, うなる
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)
5. to sing in a strong, low voice (esp. traditional chant or recitation)
6. to ...
tbd