Words changing meaning

[Steve H]

As noted in "TFGOT", "wicked" has long been used by yoof to mean roughly its opposite. A subtler change happened long ago to "like" It used to mean "to please", so if you were fond of something, you would say "it likes me", which is how Shakespeare always puts it. Now, it means "to enjoy", so we say "I like it".
"Temper" seems to be changing its meaning to the opposite of its original meaning, which was "patience, slowness to anger" at the moment. When someone says of some nasty thug "he's got a hell of a temper", they mean that he has little or no temper: temper, traditionally, is what you lose when you get angry.

[Nearly Sane]

The classic in this is surely 'nice' which meant foolish, then changed to amongst other things naughty, and now means pleasant, though if said in a certain tone implies the opposite.

[Steve H]

CS Lewis once pointed out that words meaning "smell" (noun) in general tend to move towards meaning "bad smell". "Stink" and "stench" were once neutral, and, as CSL pointed out, "smell" itself seems to be going the same way (although, since he's been dead 56 years, it's taking its time about it).

[jeremyp]

Here's one from Wittertainment...

The word "satisfactory" now means unsatisfactory.