I don't know about you but we used to joke back in the day that the computer "is thinking" when taking long to process something.

Dictionaries usually provide some kind of useless circular definition. Thinking? The act of making thoughts. Thoughts? The result of thinking. I can't believe people used to pay for these things.

In any case it's something to do with taking input data, doing something with it, and generating new data related to it. That's more or less just recursive inference.