noun Etymology: Jacob Grimm a statement in historical linguistics: Proto-Indo-European voiceless stops became Proto-Germanic voiceless fricatives (as in Greek pyr, treis, kardia compared with English fire, three, heart), Proto-Indo-European voiced stops became Proto-Germanic voiceless stops (as in Latin duo, genus compared with English two, kin), and Proto-Indo-European voiced aspirated stops became Proto-Germanic voiced fricatives (as in Sanskrit nābhi, madhya “mid” compared with English navel, Old Norse mithr “mid”)