Zen

Another approach to the question "what is Zen" from this interesting Zen/Kungfu site:

What is Zen?

Many people are confused because they are unaware that the term 'Zen' has a few meanings. Basically, the word 'Zen' means meditation. Sometimes it may refer to a transcendental glimpse of cosmic reality, or even the transcendental reality itself. Often Zen is used as a short form for Zen Buddhism. The following examples illustrate the use of 'Zen' in these four meanings:

1. I sat cross-legged on a hard pillow, closed my eyes gently and practised Zen.
2. My teacher came in and hit my head to test if I had a Zen experience.
3. I was shocked when he said he did not hit me, but years later I realized my kind teacher was trying to make me aware that there was no hitting, and no nothing, in Zen.
4. Lacking a deep understanding, many people may think Zen masters are mad.