'Detainment' definitions:

Definition of 'detainment'

From: WordNet
noun
A state of being confined (usually for a short time); "his detention was politically motivated"; "the prisoner is on hold"; "he is in the custody of police" [syn: detention, detainment, hold, custody]

Definition of 'Detainment'

From: GCIDE
  • Detainment \De*tain"ment\, n. [Cf. OF. detenement.] Detention. [R.] --Blackstone. [1913 Webster]