Synonyms for Confined (same or very similar meaning)
WordNet sense 1 (under restraint):
restrainedWordNet sense 2 (enclosed by a confining fence):
penned, fenced inWordNet sense 3 (in captivity):
captive, imprisoned, jailedWordNet sense 4 (hampered and not free; not able to act at will):
unfreeWordNet sense 5 (closely confined):
pentFrom the ODE community, based on WordNetadd/edit