What is Quaver ?
Quaver is (noun) 1. a musical note lasting half as long as a crotchet and a quarter as long as a minim (NOTE: The US term is eighth note.) 2. a tremble in the voice There was a slight quaver in her voice as she answered the judge’s question. (verb) (of voice) to shake slightly A quavering voice answered the telephone.
source: Easier English, Student Dictionary Upper Intermediate Level