Someone asked why I in my email signature I generally put the symbol ॐ
My response was:
It's just Om.
ॐ isn't really a word, so it doesn't mean something in the way that words do. It is a symbol, and symbols mean something in a different way that is harder to pin down. Arthur Frawley thinks that in an earlier age, humankind was more adept at symbolic language, and that when intellectual learning became prevalent and we began to insist upon defining everything (i.e. להגדיר things, or put fences around them) in a singular way, we lost our ability to understand the universe of meaning as many-layered. The idea is well represented in Genesis.
Placing a mysterious undefinable word that means nothing and everything and which can never be understood in any conventional way bang in the middle of the mantlepiece serves as a reminder that the tendency to define has its limitations.
Certain spiritual teachers would never sign their name as anything but ॐ
But I didn't reach that level yet.