A di-transitive verb is the verb which has got two verbs in a sentence. For example-
We all have got plans for tonight.
Here, if we ask-
* What have we for tonight?
= plans
* Who has got plans for tonight?
= We
So, the verb has two objects.
Again, we know that transitive verb is the verb which has got only one object. And, the prefix 'di' before transitive represents two objects. That's that.