Polysyndeton

Polysyndeton (from Ancient Greekπολύpoly'many' and συνδετόνsyndeton'bound together with') is the insertion of repeated conjunctions into a sentence for deliberate effect, especially to slow 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).