source: By Revolus - Image:Martinus opifex 001.jpg (PD), Public Domain

a group of advisers, assistants, or others accompanying an important person:

〖集合的に; 単複両扱い〗(王侯･貴族などの)従者, 随行［随員］(団)

e.g. the rock star's retinue of security guards and personal cooks.

late Middle English: from Old French retenue, feminine past participle (used as a noun) of retenir ‘keep back, retain’.