sacksack

The story

From Middle English sak, sek, sach, zech (‘bag, sackcloth’), from Old English sacc (‘sack, bag’) and sæċċ (‘sackcloth, sacking’); both from Proto-West Germanic *sakku, from late Proto-Germanic *sakkuz (‘sack’), borrowed from Latin saccus (‘large bag’), from Ancient Greek σάκκος (sákkos, “bag of coarse cloth”), from Semitic, possibly Phoenician or Hebrew. Černý and Forbes suggest the word was originally Egyptian, a nominal derivative of sꜣq (‘to gather or put together’) that also yielded Coptic ⲥⲟⲕ (sok, “sackcloth”) and was borrowed into Greek perhaps by way of a Semitic intermediary. However, Vycichl and Hoch reject this idea, noting that such an originally Egyptian word would be expected to yield Hebrew *סַק rather than שַׂק. Instead, they posit that the Coptic and Greek words are both borrowed from Semitic, with the Coptic word perhaps developing via Egyptian sꜣgꜣ.

Full etymology on Wiktionary