An Etymological Dictionary of the German Language/Tanne
Tanne, f., ‘fir tree,’ from the equiv. MidHG. tanne, f., OHG. tanna, signifies ‘fir tree, oak,’ hence the primary idea of the word is usually ‘forest tree’ (see Eiche, Buche). This is supported by ModHG. Tann, m., from MidHG. tan (nn), m. and n., ‘forest’' (OHG. tan-ęsil, ‘wild ass’), which seems to be based on a collective signification of Tanne. The early history of the HG. cognates (to which ODu. dęnnia, Du. den, ‘fir tree,’ is allied) is uncertain. Its connection with Gr. θάμνος, ‘thicket,’ is dubious.