Alteration of twissel, from Middle English twisel, twisil, from Old English twisla ("confluence, junction, fork of a river or road"), from Proto-Germanic *twisilą ("fork, bifurcation"), from Proto-Indo-European *dwis- ("twice, in two"). Cognate with German Zwiesel ("fork"). Compare also Icelandic kvísl ("branch, a fork; fork of a river").