Verb (5-dan, る, intransitive)
1. to groan; to moan
何も言えないで、唸るしかなかった。I couldn't say anything and could only groan.
2. to roar; to howl; to growl
俺が小さく独り言をつぶやくと、犬は警戒するように唸った。When I muttered quietly to myself, the dog growled warily.
3. to hum (engine, wind, etc.); to buzz; to whiz; to sough; to make a low, dull sound
冷蔵庫が唸るような音を立てている。The fridge is making a humming noise.
4. to ooh and aah (in admiration)
そのメニューを見てアキラが少し楽しげに唸っている。Looking at the menu, Akira lets out a slightly delighted hum.
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