Reversal of the meaning of the word "restive"

No, such reversals are not common; they are quite rare, in fact. Plaintive still connects directly to (com)plaint and fugitive still connects directly to the root also found in refuge, etc., with no reversal of meaning.

In the case of restive, it’s not that the word just suddenly happened to reverse its meaning, either. The development is actually quite logical.

The original meaning was indeed ‘resting, not inclined to move’, but the word was especially used of horses refusing to move—that typical scenario where you’re riding a horse and the horse balks at some hurdle or obstacle in the road. It refuses to go on, it becomes restive; but it doesn’t just stand still, quite at rest: it starts fidgeting back and forth, making odd little jumps and bumps this way and that.

So in comparison to the intended goal (running on and jumping over the obstacle), the horse has stopped and become restive; but in comparison to a horse that’s standing quite still and just chewing on some nice grass, the restive horse looks nervous, jumpy, and fidgety.

In time, restive started to be taken as an opposite state to the latter of these two, rather than the former: it became to fidget, be jumpy, be unable to stand quite still, and lost its original meaning of just being still as opposed to in motion.

It is not common. Examples include:

• parboil (now meaning partially boil, formerly thoroughly boil)
• sanguine (formerly meaning hot-headed, now happy-go-lucky)

I cannot think of any -ive examples. I am not aware of any systematic surveys of this, but it is rare enough to be remarkable.

Cleave is also interesting. By two different etymologies (as cleft, and as clave) it can mean wrenched apart and pushed together, and both senses have existed since Old English (Edit: though they were not originally homonyms). While this gives brassiere manufacturers a great deal of scope, you do have to wonder at whether the word remains useful.