unobserved
1. [ adjective ] not noticed
Synonyms: unseen unnoticed
Related terms: undetected
2. [ adjective ] not witnessed at first hand
Related terms: unwitnessed
3. [ adjective ] not observed
Examples:

"managed to slip away unobserved"

Related terms: unnoticed
Similar spelling:   unobservable
  unposed
  unobservant
  unbiased
  unabused
  unfocused
  unabashed
  unobjective
  unabashedly