Articles under the heading Arier were included in the big popular encyclopaedias of Brockhaus and Meyer from 1864 and 1867 respectively, and the Arier is defined from the start as Indo-Germanic. The 14th edition of Brockhaus states specifically that it is better to apply the term Arier only to "Asian Aryans" and to use the term Indo-Germanic or Indo-European to describe the "European Aryans".

Entry Aryan of Brockhaus: In modern linguistics the term Aryan is sometimes used to refer to all Indo-Germans, but the term Indo-Germans or Indo-Europeans is preferable [to describe the European Aryans], since in linguistics the term Aryan is usually only applied to the Indian and Iranian Indo-Germans. The 14th edition of Brockhaus encyclopaedia, 1896, Entry Aryan, page 870. In Poliakov, L. (1974). The Aryan myth : a history of racist and nationalist ideas in Europe