The word 持久 is formed by combining the character 持, meaning 'to hold' or 'to maintain,' with the character 久, meaning 'long time' or 'prolonged.' Together, they create a compound where 持 acts as a verb component indicating the action of sustaining, and 久 serves as an adverbial component describing the duration, resulting in the meaning 'to hold for a long time,' hence 'enduring' or 'lasting.'