The Collaborative International Dictionary of English v.0.48:

Reformatory \Re*form"a*to*ry\ (-t?*r?), a.
   Tending to produce reformation; reformative.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Reformatory \Re*form"a*to*ry\, n.; pl. -ries (-r?z).
   An institution for promoting the reformation of offenders.
   [1913 Webster]

         Magistrates may send juvenile offenders to
         reformatories instead of to prisons.     --Eng. Cyc.
   [1913 Webster]

WordNet (r) 3.0 (2006):

reformatory
    adj 1: tending to reform; "reformative and rehabilitative
           agencies"; "reformatory punishment" [syn: reformative,
           reformatory]
    n 1: correctional institution for the detention and discipline
         and training of young or first offenders [syn:
         reformatory, reform school, training school]

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "reformatory":
   POW camp, bastille, black hole, borstal, borstal institution,
   borstal school, bridewell, brig, can, cell, concentration camp,
   condemned cell, cooler, death cell, death house, death row,
   detention camp, federal prison, forced-labor camp, gaol,
   guardhouse, house of correction, house of detention,
   industrial school, internment camp, jail, jailhouse, keep,
   labor camp, lockup, maximum-security prison,
   minimum-security prison, oubliette, pen, penal colony,
   penal institution, penal settlement, penitentiary, pokey, prison,
   prison camp, prisonhouse, reform school, remand school,
   sponging house, state prison, stir, stockade, the hole, tollbooth,
   training school