What does the slang word can mean in the following sentences:
Hey guys, do you know where the can is around here?
I can't make make it to the phone; tell them I am in the can.
Finally, our planning is in the can and we can begin construction tomorrow.
After googling for an hour, I found out that the word "can" is used for toilet.
From the first 2 sentences above, I understand that a stranger in a new place was trying to find out where the toilet was, and then he went inside the toilet.
The 3rd sentence is a little confusing to me.
What was someone trying to say in the last sentence?