-ku Godan/u-verb

1. to well (up); to gush out (of water); to spring out; to surge
2. to appear (esp. suddenly) (sweat, tears, etc.); to sweat; to cry
3. to feel emotions (e.g. joy, bravery, etc.); to spring up (e.g. an idea, emotions, clouds); to well up; to arise
4. to hatch; to breed; to propagate; to be infested (esp. of parasitic insects, etc.)