An Etymological Dictionary of the German Language/zirpen

by Friedrich Kluge

zirpen, vb., ‘to chirp,’ ModHG. only; a recent onomatop. form. So too zischeln, vb., ‘to whisper,’ and zischen, vb., ‘to hiss, whiz'; ModHG. only; in MidHG., zispezen, n., ‘hissing.’