Castigate is a related term of lash.
As verbs the difference between castigate and lash
is that
castigate is to punish severely; to criticize severely; to reprimand severely while
lash is to strike with a lash; to whip or scourge with a lash, or with something like one or
lash can be to bind with a rope, cord, thong, or chain, so as to fasten.
As a noun lash is
the thong or braided cord of a whip, with which the blow is given.
As an adjective lash is
(obsolete) remiss, lax.