He succeeded by dint of perseverance and sheer hard work. (Identify the word class of the underlined phrase 'by dint of')

The phrase 'by dint of' means 'by means of' or 'because of' and consists of the preposition 'by', the noun 'dint', and the preposition 'of'. It functions as a compound preposition introducing the means by which something was achieved. Although it modifies the verb 'succeeded' (suggesting an adverbial function), as a structural classification, 'by dint of' is a prepositional phrase that introduces a noun phrase ('perseverance and sheer hard work').