Polysyndeton

Polysyndeton (from Ancient Greek πολύ poly, meaning "many", and συνδετόν syndeton, meaning "bound together with".) is the deliberate insertion of conjunctions into a sentence for the purpose of "slow[ing] up the rhythm of the prose" so as to produce "an impressively solemn note."

In grammar, a polysyndetic coordination is a coordination in which all conjuncts are linked by coordinating conjunctions (usually and, but, or, nor in English).