治本

to take radical measures / to get to the root (of a problem etc)

to tackle a problem at its root; to effect a permanent solution (contrasted with 治標|治标[zhi4 biao1])

to rule / to govern / to manage / to control / to harness (a river) / to treat (a disease) / to wipe out (a pest) / to punish / to research

root / stem / origin / source / this / the current / original / inherent / originally / classifier for books, periodicals, files etc

the Greenwich meridian

to treat the symptoms but not the root cause