ALL meanings of internal reconstruction
in·ter·nal re·con·struc·tion
I i - noun internal reconstruction the hypothetical reconstruction of an earlier stage of a language or of some part of it, as its phonology, by deductions from irregularities in its present structure, as the reconstruction of a stage in English when certain instances of r were related to s in a systematic way by comparing the pair was:were to other pairs, as lose:forlorn. 1