Origins
The word 'typhoon' has one of the most debated and fascinating etymologies in English, involving the convergence of at least three unrelated language families. It is a textbook case of what linguists call 'convergent etymology' — separate words from different sources that, due to phonetic similarity and shared semantic territory, merged into a single term.
The three primary sources are:
First, Greek 'Τυφῶν' (Typhōn), the monstrous son of Gaia and Tartarus in Greek mythology, who challenged Zeus and was imprisoned beneath Mount Etna. His name was associated with violent storms and volcanic eruptions, and the derivative 'τυφώς' (typhōs) meant 'whirlwind.' This entered Latin as 'typhon.'
Greek Origins
Second, Arabic 'طوفان' (ṭūfān), meaning 'deluge' or 'great flood,' used in the Quran to describe the Flood of Noah. Some scholars believe this Arabic word was itself borrowed from Greek 'typhōn,' while others consider it a native Semitic formation. Arab sailors carried the word throughout the Indian Ocean.
Third, Chinese '大風' (dàfēng in Mandarin, 'daai fung' in Cantonese), meaning 'great wind.' Some scholars cite the Cantonese dialect form 'tai fung' as the more direct source. Chinese mariners had used this term for centuries to describe the violent storms of the western Pacific.
When Portuguese explorers reached the China Sea in the sixteenth century, they encountered all three linguistic traditions in the same waters. Arab traders used 'ṭūfān,' Chinese sailors spoke of 'tai fung,' and the Portuguese themselves knew the classical Greek 'typhon.' The phonetic resemblance among all three words was close enough that they blended. Portuguese adopted 'tufão,' Spanish adopted 'tifón,' and English, through these intermediaries and through direct contact, arrived at 'typhoon.' The earliest English attestation is from 1588.
Later Development
The spelling was unstable for centuries — 'touffon,' 'tuffon,' 'tiphon,' 'tycoon' (briefly confused with a different Japanese word) — before 'typhoon' became standard in the eighteenth century, likely influenced by the desire to connect the word visibly with the Greek Typhon.
In modern meteorology, 'typhoon' refers specifically to a tropical cyclone with sustained winds of 64 knots (119 km/h) or greater in the northwestern Pacific basin. The same phenomenon is called a 'hurricane' in the Atlantic and eastern Pacific, and a 'cyclone' in the South Pacific and Indian Ocean. The differences in naming are purely geographical conventions, not meteorological distinctions.
Japanese adopted the word back as '台風' (taifū), using characters meaning 'platform/pedestal wind' — a phonetic approximation that replaced an older term '颱風.' This round-trip borrowing — Chinese word contributes to English 'typhoon,' which influences Japanese 'taifū' — illustrates the circular paths words can travel in a multilingual world.