unnoticed adj.
VERBS be, go, lie, pass The ticket lay unnoticed in my desk drawer for a week. His remark passed unnoticed. | remain
ADV. completely, entirely There's a good chance my absence will go completely unnoticed. | almost, practically, virtually | largely | hitherto, previously a hitherto unnoticed detail
You can also check other dicts: unnoticed (English, 中文解释 ), wordnet sense, Collins Definition