Since the middle of the 20th century, philosophers and legal scholars have debated the precise definition of punishment. This chapter surveys the debate, identifies six potential conditions of punishment, and critically reviews each of them: 1) the response condition, which holds that punishment must be in response to wrongdoing, 2) the culpability condition, which holds that punishment must be of a person morally responsible for wrongdoing, 3) the authority condition, which holds that punishment must be imposed by a relevant authority, (...) 4) the hard treatment condition, which holds that punishment must impose hard consequences on the punishee, 5) the intentionality condition, which holds that punishment must be intentional, and 6) the censure condition, which holds that punishment must communicate disapproval. The article argues that it is often unclear that there is a version of the condition that provides optimal lexical fit. It discusses the implications of this analysis, and concludes that there may be less reason to worry about the lack of an authoritative definition than has sometimes been assumed, but that definitional clarity remains an objective worth pursuing. (shrink)