tornado
Pronunciation: /tɔːˈneɪdəʊ/
noun ( plural tornadoes or tornados)

Origin:
mid 16th century (denoting a violent thunderstorm of the tropical Atlantic Ocean): perhaps an alteration of Spanish tronada 'thunderstorm' (from tronar 'to thunder') by association with Spanish tornar 'to turn'

Spelling help
The plural of tornado can be spelled either tornadoes or tornados.