A person who criticizes harshly or beats; someone who delivers scolding or punishment.
From Latin fustigator, derived from fustigare meaning to beat, with the agent suffix -or indicating the person who performs the action.
This word survived in English mostly as a bookish and humorous term—if you called your strict teacher a 'fustigator,' you were using Latin-rooted language to complain about punishment while maintaining a veneer of learning.
Complete word intelligence in one call. Free tier — 50 lookups/day.