I found his pretentious demeanor quite disconcerting.

I was most disconcerted.

That was disconcerting.

It was disconcerting.

Tom was disconcerted by the announcement.

As people age, we find it disconcerting to realize that increasing amounts of our skin and more of our body parts are hanging loosely about ourselves.

It's disconcerting.

Tom looked somewhat disconcerted.

The alacrity with which she was greeted felt disconcerting, given the chilly reception she had experienced before.

I don't mean to disconcert you, but there's a spider in your hair.