niddā נִדָּה ‘impurity’ (Hebrew)

Etymology^?: from nādad נָדַד ‘to wander’
Roots: נדד

niddā n, f
1) impurity, filthiness, menstruous, set apart
 1a) impurity
  1a1) of ceremonial impurity
  1a2) of menstruation
 1b) impure thing (fig.)
  1b1) of idolatry, immorality