Jonas Agree in terms of "chastity device", but think chastity-belt must include, well, a belt. Too literal of me?
It all depends on the language. In English, there are indeed "chastity belt" and "chastity device", with the latter being the broader term. However, there are languages where there is no meaningful equivalent for "chastity device", only the equivalent of "chastity belt" as a generic term. This is in my native Polish language. It seems to me that it is similar in German and French, but their users should comment on this issue. Therefore, by "chastity belt" I mean anything that is designed to prevent sex and masturbation, whether it has a belt or not.