What term refers to the systematic formulation that separates Latin from Old English and Germanic words based on their introduction?

The term that refers to the systematic formulation that distinguishes between Latin and Old English as well as Germanic words based on their introduction is Grimm's Law. This principle outlines the sound changes that occurred in the transition from Proto-Indo-European to Germanic languages, thus helping to elucidate the differences in vocabulary and phonetics between these language families.

Grimm's Law specifically demonstrates how certain consonants transformed as the Germanic languages evolved, which allows scholars to trace back linguistic roots and categorize words appropriately. This systematic approach is crucial for understanding the evolution of the English language and its relationships with other languages, especially those of the Latin and Germanic origins.

The other terms mentioned do not directly relate to the historical linguistics focus in the context provided by Grimm's Law. Phonetic Law generally concerns the rules governing sound changes in languages but does not specifically address the separation of vocabulary origins. Lexical Shift pertains to shifts in meaning and usage of words rather than their historical introduction. Etymological Standard could refer to the principles guiding the study of word origins but lacks the specific systematic aspect of sound changes and classification found in Grimm’s Law.