The story you may have heardTwo famous stories each hold a grain of truth. Many dictionaries derive typhoon from Cantonese taai fung 'big wind', but the Portuguese and Arab sailors' word came before Europeans traded at Canton, and Wikipedia traces Chinese 颱風 itself to Hokkien hong-thai. Chinese may only have nudged spellings like tyfoon. Greek Typhōn, the storm giant, had given English 'typhon, whirlwind' by the 1550s, and it shaped the y and ph of typhoon. Neither is the root of the sailors' word. Whether the Aramaic word behind ṭūfān goes back to Greek is a separate theory that remains unproven.