insider

باللغة العربية: مُطَّلِعٌ مِنَ الدَّاخِل، عَلِيمٌ بِالبَوَاطِن

1. A person who has special knowledge about the inner workings of a group, organization, or institution. · Near-synonyms: initiate, old hand, habitué
2. A person who is within an enclosed space.

الجمع insiders