detainer

Borrowed from Anglo-Norman detener, from Old French detenir. By surface analysis, detain +‎ -er (action noun suffix). First attested in the 17th century.

detainer (plural detainers)

1. (law) The right to keep a person, or a person's goods or property, against his will. A type of custody.
   • 2007 August 21, Kareem Fahim, “Presidential Candidate Blames Killings on Newark Sanctuary Policy”, in New York Times‎:

     On Monday, the federal Immigration and Customs Enforcement agency placed a similar detainer on Melvin Jovel, 18, who on Sunday was the sixth person to be arrested in the case.

   • 2008 March 23, Kareem Fahim, “Immigration Referrals by Police Draw Scrutiny”, in New York Times‎:

     Scott Weber, the field office director for the enforcement office in Newark, said that in roughly a third of the cases, his agency would file a detainer or immigration charges; another third involved individuals who could be deported after their court cases; and the rest might be United States citizens or legal residents.

   • 2008 April 13, Christine Hauser, “U.S. Officials Are Expected to Charge Police Officer”, in New York Times‎:

     Officer Torres’s lawyer, Paul S. Missan, said on Saturday that he had been told by a prison official in Pennsylvania that a detainer was lodged against his client, meaning he was likely to face federal charges.

• unlawful detainer

detain +‎ -er (agent noun suffix)

detainer (plural detainers)

1. One who detains.
   • 1840, Ellen Pickering, Who shall be heir?, volume 1, page 146:

     […] he chatted gaily with his fair detainer, showing no inclination to escape from the bondage in which she sought to retain him.

• Naderite, aditeren, antideer, redetain, retained