unobserved
adjectiveUK /ˌʌnəbˈzɜːvd/
US /ˌʌnəbˈzɜːrvd/
Not seen or noticed by anyone.
The cat slipped into the kitchen unobserved.
OTHER MEANINGS
2. Not watched or monitored, especially in a scientific or official way.
The experiment continued unobserved for several hours.
3. Not followed or obeyed, as of a rule or custom.
The old tradition went unobserved this year.
4. Not celebrated or marked, as of a holiday or occasion.
Her birthday passed unobserved because everyone was busy.