whipping post
a post to which a person is bound, often using chains or ropes, for public punishment or humiliation, typically involving whipping
en-GB/ˈwɪpɪŋ ˈpəʊst/
en-US/ˈwɪpɪŋ ˈpoʊst/
a post to which a person is bound, often using chains or ropes, for public punishment or humiliation, typically involving whipping