Can be expected to; planning to. — Used after "is" (or "was", etc.), with an infinitive, in the same way "will" is used, to show future.
Some day that big tree is going to rot and fall.
Look at those dark clouds. It's going to rain.
The boys are going to practice football this afternoon.
For a minute Ben thought the car was going to hit him.
I was going to attend the meeting, but after supper I forgot about it.
- Sometimes used without the infinitive.
That worn rope hasn't broken yet, but it's going to.
"Put some more wood on the fire." — "I'm going to."
Compare: ABOUT TO (1).