solitary confinement
noun /ˌsɒlətri kənˈfaɪnmənt/
/ˌsɑːləteri kənˈfaɪnmənt/
(also informal solitary)
[uncountable]- a punishment in which a prisoner is kept alone in a separate cell
- to be in solitary confinement
- He spent eleven years in solitary confinement.