Where does “tigern” come from?

tigern (German) comes from German Tiger, from Latin tīgris, from Ancient Greek Τίγρις, from Old Persian 𐎫𐎡𐎥𐎼𐎠, from Akkadian 𒀀𒇉𒈦𒄘𒃼, from Sumerian 𒀀𒇉𒈦𒄘𒃼 — as fast as an arrow.

tigern (German): to pace, walk back and forth like a caged animal, often nervously