If she had a nice arse you could say she has cheeks like Rosey but if she had high blood pressure you would say she had rosy cheeks.
In other words the correct answer is "nosy", but because so many simpletons were getting it wrong and spelling it, "nosey", eventually the powers that be had to give in and say that, "nosey" was also correct. Another victory for the stupid.
Point of order, but are they not the 'same words in a different order' rather than the 'other words' you suggested?