IPA: /ˈkwɛvərɪŋli/
KK: /ˈkwɛvərɪŋli/
In a way that shows trembling or shaking, often due to fear or nervousness.
She spoke quaveringly, her voice shaking with fear.
Quaveringly is formed from "quaver" (from Old English "cwafian", meaning to shake or tremble) and the suffix "-ly" (meaning in a manner of). The word describes doing something in a manner that shakes or trembles.
Think of the word 'quaver' which means to shake or tremble, and remember that 'quaveringly' means doing something in a trembling manner.