köken: From Middle High German grānāt which was borrowed from Medieval Latin granatus, most likely a substantivized masculine form of *lapis granatus.. More at Granatapfel. The term Granat in the sense of shrimp was borrowed from Middle Low German garner, garnat or garnol, itself borrowed from Middle Dutch grenat (as spoken in Flanders).
köken: The weapon and mineral are named after the fruit. Latin pomum granatum means an apple with many seeds, from Latin granum (“seed”). Spanish influence formed the French grenade, which became granat in German, Danish, and Swedish. Used in Swedish since 1578 (fruit, the compound granatäpple already in 1541), 1568 (mineral), 1623 (weapon).
Inherited from Middle Persian (cf. Arabic بِجَادَق (bijādaq)), by surface analysis, بی (bi, “without”) + جاده (jâde, “road, (here: streak)”). Compare Old Georgian ბეჭედი (beč̣edi), Armenian պիճատի (pičati), Iranian borrowings.