NickM said:
By which I mean that people on the radio nowadays generally refer to the planet Uranus when what they really mean is Uranus (as we all know)...
Not as daft as you might think. The original word is the Greek 'Ouranos', which was always pronounced with the stress on the first syllable and a short 'a'.
Unlike many European languages, English doesn't like stressing the first syllable of words, and moving the stress to the second syllable naturally makes people pronounce it with a long 'a', maybe making the false derivation with anus.
Another example is homosexual. People assume it's from the Latin, homo, as in Homo Sapiens, so it is pronounced with two long 'os'. In fact although it's a fabricated word, the first part was from the Greek 'homoio' [=same], as in homogeneous, i.e with both 'os' short.
So there.
