quaver
n. US //ˈkweɪvɝ// UK //kwˈeɪvɐ// qua·ver
From Middle English quaveren, frequentative form of quaven, cwavien (“to tremble”), equivalent to quave + -er. Cognate with Low German quabbeln (“to quiver”), German quabbeln, quappeln (“to quiver”). More at quave, quab, quiver.