Noun
sublist (plural sublists)
A list that makes up part of a larger list.
Initially, the sorted sublist is empty and the unsorted sublist is the entire input list. Source: Internet
Top-down implementation Example C-like code using indices for top down merge sort algorithm that recursively splits the list (called runs in this example) into sublists until sublist size is 1, then merges those sublists to produce a sorted list. Source: Internet