In my time in Japan I've noticed a few kanji that can be used on their own commonly in various kinds of signs, yet I don't think they are also words in their own right:
- 押
- 引
- 危
- 開
- 閉
Since all kanji have multiple readings, I keep wondering how native speakers read these, or talk about them.
In fact for 危 I'm also interested in what they read it semantically. Is it "dangerous", or "watch out" or "caution" - or does it not really matter until you try to put it into words?