How is it traditionally defined the minimum wage legislation in economics? And which countries does not have a minimum wage legislation as defined in these terms?
It depends. Some countries use hourly wage (Australia, Morocco, UK, US), other use daily (Mexico), other monthly (Argentina, Brazil, Chile, Colombia, France, Peru, Spain), others annually (Bolivia). (this is not an exhaustive list)
Countries without a minimum wage established by law are: Denmark, Iceland, Italy, Norway, Sweden, Switzerland. They do however have minimum wages negotiated at the trade union level, even at industry level.
Given this information, the "traditionally" adjective you are using is not very helpful.