I don’t like ‘hysterical’ used to mean ‘hilarious’, but I wonder if it has evolved into correct usage now. ‘ John slipped on a banana skin, and it was hysterical’.
Some of the problem is getting old, of course
. We were taught that ‘hopefully’ meant ‘with hope’, not ‘with any luck’, but the meaning has changed now. I also think that it is now acceptable to say ‘different to’ instead of ‘different from’, when it used to be considered American usage (and therefore the work of the Devil, according to my English teacher). Both sound wrong to me, but life moves on.