noun Date: circa 1550 one that observes: as, a representative sent to observe but not participate officially in an activity (as a meeting or war), an expert analyst and commentator in a particular field
OBSERVER
Meaning of OBSERVER in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012