1) Monitor 2) Proctor 
Someone who ensures the smooth running of exams. An invigilator is responsible for ensuring that the Awarding Body's regulations are complied with; that exams start and finish at the correct time; that exam papers are secure whilst in their care; that attendance and seating plans are recorded; and that no cheating takes place. The invigilator will ...
[n] - (British) someone who watches examination candidates to prevent cheating