What is another word for keep in custody?
Pronunciation: [kˈiːp ɪn kˈʌstədi] (IPA) 
There are various synonyms for the phrase "keep in custody," which refers to detaining or imprisoning someone. Common synonyms include holding, confining, detaining, restraining, and incarcerating. Other related terms include locking up, restraining, controlling, and restricting. These phrases all refer to the act of keeping someone in a secure location or under close watch. The specific choice of synonym will depend on the context and the severity of the situation. For example, "incarcerating" is a more formal or serious term than "holding," which may be used in a more casual setting. Nonetheless, all of these terms express the idea of keeping someone under strict supervision or confinement.
