The thing that bugs my husband is everyone mispronouncing 'Helicopter'
It isn't: 'He-li-cop-ter', it should be: 'He-li-co-pter', but the 'p' is silent so it should be:
'He-li-co-ter'

It literally means spiral or helical wing - 'Pter' being ancient-dead-people-speak for wing(s) or winged.