Synonyms for Undisciplined (same or very similar meaning)
WordNet sense 1 (not disciplined or conditioned or made adept by training):
untrained
WordNet sense 2 (not subjected to correction or discipline):
uncorrected
WordNet sense 3 (not punished):
unpunished
WordNet sense 4 (lacking in discipline or control):
ungoverned
WordNet sense 5 (not being under control; out of control):
uncontrolled
From the ODE community, based on WordNet
add/edit