lautverschiebungen

Lautverschiebung \Laut"ver*schie`bung\
   (lout"f[e^]r*sh[=e]`b[oo^]ng), n.; pl. {Lautverschiebungen}
   (lout"f[e^]r*sh[=e]`b[oo^]ng*en). [G.; laut sound +
   verschiebung shifting.] (Philol.)
   (a) 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}.
   (b) 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.
       [Webster 1913 Suppl.]