Another word, good only for a certain kind of audience, is flatten. To flatten a list, in certain programming languages, is to remove nesting structure. Thus, for example, in the Mathematica programming language, one begins with the list:
{{a, b}, {c, {d}, e}, {f, {g, h}}}
which has several depths of nesting. Here the braces "{A}" stand for "push"or "indent" object "A" to a one level deeper nesting. A call of the verb "Flatten" i.e.
Flatten[{{a, b}, {c, {d}, e}, {f, {g, h}}}]
outputs the list
{a, b, c, d, e, f, g, h}
and there is a variation where you can specify how many levels of nesting you want to get rid of; for example:
Flatten[{{a, b}, {c, {d}, e}, {f, {g, h}}}, 1]
gets rid of only one level of nesting to output
{a, b, c, {d}, e, f, {g, h}}
The generalization of this idea is to replace recursion by iteration and contrariwise; this is done often to optimize an algorithm for a particular language: imperative languages work best with iteration and functional languages best with recursion. Notwithstanding the heavy usage of this notion of transforming one to the other, there doesn't seem to be a word in general usage in computer science for this notion.