Killing time is engaging in actions solely for the purpose of keeping busy, especially during periods in which what one can do is limited, for example after arriving early for an appointment.
The idiom to kills/slaughter the fattened calf basically means that you will celebrate with a friend or relative that you have not seen in a very long time.
"Time to kill" refers to situations where you unexpectedly have more time than you thought you would, and now you must find some way to fill that time. For example: you don't need to be somewhere till 5 pm, but you got there at 4 pm; now you have an hour to kill. You can just sit around and wait, or read a book, or check your email, or make a call, etc.
It's not an idiom - it means just what it says. Something took "no" time to come about. It's an exaggeration, but the meaning is plain.
This isn't an idiom. It means just what it seems to mean. Something is only a matter of time - you only have to wait until it happens.
It is just an exaggerated way of saying something happens quite often - it is hyperbole, not an idiom.
it means when you are really nervous and cool at the same time.:)
It takes a long time to do an important job
The idiom "a dog's age" means a long time or a period that feels particularly long. It exaggerates the notion of time passing slowly, similar to saying "an eternity."
The sentence is not, because an idiom is usually a phrase. The idiom is "do lunch," which means to have lunch together, usually while discussing business.
This is not an idiom. It means just what it says. It is a saying that means time seems to go by more quickly when you are doing something enjoyable than it does when you are uncomfortable.
Let's do lunch some time next week.
If you have your hands full, you can't do anything else with them, can you? This idiom means that you're overloaded and don't have time or ability to do anything else.