"compile" is valid, especially if the resulting source is in some way lower-level or more unstructured than the original. "translate" is also used, and in fact is official terminology in some languages even for source-to-object-code compilations: last I checked (I haven't kept up with the 2011 standard) the C++ standard specified that source code was organized into "translation units" that usually correspond to files but could theoretically be anything. "transpile" is a less common coinage presumably aiming to distinguish the case where the output is still human-readable; I find it ugly and mostly avoid it.