울렁거리다

1. palpitate; throb; thump
For one's heart to keep beating because one has been startled or scared by something.

2. feel nausea; feel sick
To feel like vomiting continuously because one feels sick in their stomach.

3. waver; fluctuate
For a wave to keep rising and falling.

4. waver; move in a wavelike pattern
For a thin board, etc., to keep swaying as if it were being bent.