pe ‧ nal /ˈpiːnl/ BrE AmE adjective
[ Date: 1400-1500 ; Language: French ; Origin: pénal , from Latin poenalis , from poena 'punishment' ]
1 . [only before noun] relating to the legal punishment of criminals, especially in prisons:
the penal system
penal colony/settlement (=a special area of land where prisoners are kept)
2 . penal servitude law when someone is punished by being kept in prison and made to do hard physical work
3 . British English very severe:
penal rates of interest