lautverschiebung

from The Century Dictionary.

• noun In philology, ‘shifting of sounds’: applied to the changes which a series of regular Indo-European mute consonants of the same class underwent in the Teutonic languages, as if each consonant were shifted forward one degree in its class. See Grimm's law, under law. A later shifting, sometimes called the second lautverschiebung, appears in the Old High German.

from the GNU version of the Collaborative International Dictionary of English.

• noun The regular changes which the primitive Indo-European stops, or mute consonants, underwent in the Teutonic languages, probably as early as the 3d century b. c. , often called the first Lautverschiebung, sound shifting, or consonant shifting.
• noun A somewhat similar set of changes taking place in the High German dialects (less fully in modern literary German) from the 6th to the 8th century, known as the second Lautverschiebung, the results of which form the striking differences between High German and The Low German Languages. The statement of these changes is commonly regarded as forming part of grimm's law, because included in it as originally framed.