castigar
punish
castigate
to criticize or punish severely
+
-ar
verb suffix
Castigar means to punish and can be thought of as castigate0 (to criticize or punish severely0) + -ar1 (verb suffix1).
verb
  1. punish
    To punish or penalize someone for their actions
    Los padres decidieron castigar a su hijo por su mal comportamiento. // The parents decided to punish their son for his bad behavior.