It's an odd word. I saw it used in a Twitter explanation.
Basically, you'd use it to say that you've been heavily thinking or calculating about something....usually over an extended or prolonged period, and it suggests that you can't come to a happy solution.
How you'd use it? You would say: I spent the entire afternoon....trying to ruminate about the problem.
A new term? No.....the word people suggest this goes back to 1533, where some guy needed to explain something....and he likely pulled this word out of thin air to get the problem across to his associate.
The general problem here with ruminate....in most problems, you can throw the mess on a white-board, and in three minutes....draw some kind of conclusion or end-point, with a rational list of solutions.
The minute you insert a money limit, a manhour issue, a potential failure ending, or a benefit-gained scenario....then you enter the world of ruminate. That five-minute pause to think will twist and turn into an hour or two.
To be honest, if you polled folks....a majority of people have never entered the stage of ruminate, and probably have never wasted more than 15 minutes in their life over thinking about a problem.
