The phrase "tan someone's hide" is an idiomatic expression that means to punish someone severely, especially by physical means. There are a number of synonyms for this phrase, which can be used to convey a similar idea in slightly different ways. Some synonyms for "tan someone's hide" include "whip someone into shape," "teach someone a lesson," "put someone in their place," "give someone the business," and "bring someone to heel." Each of these phrases suggests a different approach to discipline, but they all convey the idea of imposing consequences on someone who has done wrong.