WordNet sense 1 (not tractable; difficult to manage or mold):

intractable

WordNet sense 2 (of persons):

ungovernable, unruly, indocile

WordNet sense 3 (difficult to manage or control):

difficult, unmanageable

WordNet sense 4 (incapable of being controlled or managed):

uncorrectable

WordNet sense 5 (impervious to correction by punishment):

incorrigible

WordNet sense 6 (impossible to repress or control):

irrepressible