What is the X in X-mas?
mid-15c., from Middle French détention (13c.), from Late Latin detentionem (nominative detentio), noun of action from past participle stem of Latin detinere (see detain). Sense of "confinement" used by 1570s (in reference to Mary Queen of Scots). In reference to school punishment, recorded from 1882.
the practice of incarcerating accused individuals before trial on the assumption that their release would not be in the best interest of society-specifically, that they would be likely to commit additional crimes if they were released. Preventive detention is also used when the release of the accused is felt to be detrimental to the state's ability to carry out its investigation. In some countries the practice has been attacked as a denial of certain fundamental rights of the accused.