The Collaborative International Dictionary of English v.0.48:

Schoolship \School"ship`\, n.
   A vessel employed as a nautical training school, in which
   naval apprentices receive their education at the expense of
   the state, and are trained for service as sailors. Also, a
   vessel used as a reform school to which boys are committed by
   the courts to be disciplined, and instructed as mariners.
   [1913 Webster]