[{"Bold_text": "noun", "List Items": ["a person or thing that retains.", "a servant or attendant who has served a family for many years.", "Also called cage , separator .Machinery.a ring separating, and moving with, balls or rollers in a bearing.", "Orthodontics.a fixed or removable device worn in the mouth to hold the teeth in their new position during the adaptive period after straightening appliances have been removed.Prosthodontics.a part on a bridge or the like by which the bridge is attached to the natural teeth.", "a fixed or removable device worn in the mouth to hold the teeth in their new position during the adaptive period after straightening appliances have been removed.", "Prosthodontics.a part on a bridge or the like by which the bridge is attached to the natural teeth."]}, {"Bold_text": "noun", "List Items": ["the act of retaining one's .", "the fact of being so retained .", "a fee paid to secure services, as of a lawyer."]}]