re·cal·ci·trant 
(rĭ-kălsĭ-trənt)
(rĭ-kălsĭ-trənt)adj.
1. Stubbornly resistant to or defiant of authority or guidance. See Synonyms at obstinate.
2. Difficult to manage or deal with: a recalcitrant problem.
3. Resistant to chemical decomposition; decomposing extremely slowly.
n.
A recalcitrant person.
[Late Latin recalcitrāns, recalcitrant-, present participle of recalcitrāre, to be disobedient, from Latin, to deny access : re-, re- + calcitrāre, to kick (from calx, calc-, heel).]
re·calci·trance, re·calci·tran·cy n.