An Etymological Dictionary of the German Language/Annotated/Hammer
Hammer, masculine, ‘hammer, clapper,’ from the equivalent Middle High German hamer (plural hęmer), Old High German hamar (plural hamarâ), masculine; compare Old Saxon hamur, Anglo-Saxon hamor, masculine, English hammer, and its equivalent Old Icelandic hamarr, masculine (also ‘cliff, rock’); the common Teutonic word for ‘hammer,’ by chance not recorded in Gothic only. For the elucidation of its earlier history the subsidiary meanings in Scandinavian are important; the cognate term kamy in Old Slovenian signifies ‘stone.’ Hence it has been assumed that Hammer is literally ‘stone weapon.’ Whether Sanscrit açman, ‘rock, stone weapon, hammer, anvil,’ &c., and Greek ἄκμων, ‘anvil’ (Lithuanian aknmů, ‘stone’), are also allied is uncertain.