An Etymological Dictionary of the German Language/Annotated/Speck
Speck, masculine, ‘bacon, lard, fat,’ from the equivalent Middle High German spëc (ck), Old High German spëcch, masculine; corresponding to Dutch spek, Anglo-Saxon spic, Old Icelandic spik, neuter, ‘blubber.’ A primitively Teutonic term, which is usually connected with Sanscrit pîvan, ‘fat,’ Greek πίων, ‘fat,’ Zend pivaṅh, ‘bacon,’ the w being assumed to be changed into q (see feck and Speichel).