Main Entry: de·po·lar·iza·tion Variant: or Britishde·po·lar·isa·tion/(")dE-"pO-l&-r&-'zA-sh&n/ Function: noun : loss of polarization; especially: loss of the difference in charge between the inside and outside of the plasma membrane of a muscle or nervecell due to a change in permeability and migration of sodium ions to the interior